Center for Research on Information Systems. Computer ... This real scenario calls for the database .... Our evaluation of query languages centers around several.
QUERY LANGUAGES
-
A TAXONOMY
Yannks V a s s i l i o u and Matthias J a r k e
Center f o r Research on Information Systems Computer A p p l i c a t i o n s and Information Systems Area Graduate School of Business AdministratTon New York U n i v e r s i t y
Workknq Paper Serjces CRIS #34 GBA #82-35
(CR)
T h i s p a p e r was o r i g i n a l l y p r e s e n t e d a t : NYU amposkum -
on User I n t e r f a c e s New York, NY, May, 1982
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 3
1
.
INTRODUCTION A h y p o t h e t i c a l f u t u r i s t i c s c e n a r i o f o r querying a
database
begins w i t h a u s e r s i t t i n g on t h e couch, s i p p i n g some c o f f e e and l o o k i n g a t t h e fancy d i s p l a y of h e r personal computer it h e r t e l e v i s i o n s e t ?
-
understands h e r i n t e n t i o n s , t h e p e r s o n a l her
favorite
format.
To
computer
is
voice
in
presents
an
break t h e monotony, she
-
i s s u e s h e r next r e q u e s t p r a c t i c i n g h e r French simulated
company,
J u s t l i k e h e r b e s t f r i e n d who always
c a t e g o r i z e d by department.
in
is
She s c r a t c h e s her head and i n s t r u c t s t h e
p e r s o n a l computer t o d i s p l a y t h e monthly s a l e s f o r h e r
answer
or,
the
reply
by
t h e same language, a l i t t l e bad i n t h e
accent.
But l e t us d e a l with Architecture with
a
Machine
voice
Group
and
"Put-That-There".
the
This
reality at
gesture real
of
the
present.
MIT [ScHu 821 i s experimenting interactive scenario
system
called
c a l l s f o r t h e database pointing)
u s e r t o i s s u e h e r commands by voice and g e s t u r e ( e . g . and
The
by
positioning her eyes a t t h e d e s i r a b l e o b j e c t i n a large
screen.
The u s e r wears a headset microphone, has a watchband on
her
wrist
for
the
gesture
recognizer,
i s wired a s i f t o be
e l e c t r o c u t e d and s i t s i n a media room.
A t h i r d s c e n a r i o i s r e q u i r e d t o d e s c r i b e t h e most r e a l i s t i c
circumstances
for
i n t e r a c t i v e l y querying a d a t a b a s e .
The u s e r
s i t s i n f r o n t of h e r CRT t e r m i n a l , makes s u r e s h e h a s t h e description
of
the
database
-
right
which f i e l d appears where, what
r e l a t i o n s h i p s e x i s t between t h e d a t a
-
and
starts
typing
the
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 2
ABSTRACT A taxonomy of database query languages i s p r e s e n t e d based on a n a n a l y s i s of e x i s t i n g languages and c u r r e n t t r e n d s i n r e s e a r c h and p r a c t i c e . The c a t e g o r i z a t i o n of query languages i s hierarchical. A t t h e senses l e v e l , languages a r e d i s t i n g u i s h e d At a a c c o r d i n g t o t h e c l u e s and senses employed by t h e u s e r . more detailed level, the methods l e v e l , languages a r e c a t e g o r i z e d according t o t h e b a s i c concepts, methodologies and conceptual u s e r models which a r e employed. In addition t o t h i s c a t e g o r i z a t i o n , t h e taxonomy i n c l u d e s schemata of e v a l u a t i o n c r i t e r i a t o be used i n language comparisons. Using t h e r e s u l t s of human f a c t o r s s t u d i e s , t h e e v a l u a t i o n schemata a r e a p p l i e d t o t y p i c a l u s e r p r o f i l e s t o d e r i v e u s a b i l i t y recommendations. The u s e r p r o f i l e s a r e p a r t of a comprehensive c l a s s i f i c a t i o n scheme of query language u s e r s a l s o developed i n t h i s paper.
We a r e g r a t e f u l t o our c o l l e a g u e Margrethe Olson f o r h e r comments and s u g g e s t i o n s on t h e f i r s t d r a f t . W e would a l s o l i k e t o thank Martha Hart Deese f o r doing a n e x c e l l e n t job t y p i n g t h e t a b l e s i n t h i s paper.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 4
Is i t FIND o r GET I have t o use h e r e , do
q u e r y on t h e keyboard.
I p u t t h e GROUP BY b e f o r e t h e WHERE?
"ILLEGAL
After
COMMAND".
Then a p p e a r s t h e
message:
two more t r f e s she g e t s t h e answer,
b u t i s t h i s what s h e wanted?
What a l l of t h e s e s c e n a r i o s have i n Ldentificatkon
of
our
hypothetical
i n f r e q u e n t u s e r with l i t t l e o r no novice
user
user
as
programming
a
i s
natural
a "novice"; knowledge.
an The
l i k e l y wants t o s t a y away from a p r o g r
most
language, pays l i t t l e a t t e n t f o n
little
common
to
precision
and
logic,
has
s e n s e of a l g o r i t h m i c t h i n k i n g , and e x p e c t s t h e system t o
respond t o h i s
or
her
personal
style.
Our
preference
for
f o c u s i n g on t h e novice u s e r f n our s c e n a r i o s s h o u l d n o t b e t a k e n a s an i n t e n t i o n t o i g n o r e a l l o t h e r t y p e s of u s e r s . should
be
Rather,
t a k e n a s a r e a l i z a t i o n t h a t t h e p o p u l a t i o n of novice
u s e r s i s i n c r e a s i n g a t l e a s t p r o p o r t i o n a l l y with t h e computer
and knformation systems.
equipment
t y p e s of system database
it
users
can
interacthn
benefit
languages
human f a c t o r s p r i n c i p l e s
of
a
if
the
takes
knto
language
growth
of
Regardless, o t h e r des2gn
of
thekr
conskderatkon t h e
system
designed
for
where
some
novices.
The t h r e e hypothesize
we
scenarios are
give
goLng,
an
what
indkcation
of
d k r e c t i o n we a r e t a k i n g , and
where we a r e today with d a t a b a s e q u e r y languages.
The number and v a r i e t y under
development
bas
of
query
languages
available
or
become s o confuskng t h a t a framework 2 s
needed f o r c l a s s i f y i n g and e v a l u a t k n g q u e r y languages
in
terms
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 5
of t h e i r u s a b i l 2 t y by d i f f e r e n t t y p e of u s e r s .
3s
paper
to
establish
such
from it.
recolnmendatfons
a
Our g o a l i n t h i s
framework
and
to
I n t h i s r e s p e c t , our work goes beyond
p r e v i o u s surveys and c a t e g o r i z a t i o n s t h a t have appeared
[LOTS 811, EMcMc 8 2 1 ,
Our taxonomy i s observation
the
of
two
[S~RQ 771 ) .
a
two-level
language
engineering*
hierarchy
grounded
in
the
converging t r e n d s which seem t o govern t h e
r e c e n t development of query
necessary
in
I [BCS 81 1 , [LaPi 76,77,801 , [LeBl 791 , [LeSa 741 ,
literature
formal
derive
theory
languages;
and
the
one
other
orfginating
from
S e c t i o n 2 expands on t h k s 2dea
human
after
from
factors
giving
the
d e f i n i t i o n s and narrowing t h e scope of t h e p a p e r t o a
manageable t a s k .
In Section 3 ,
describing
the
senses
level,
languages
a r e c l a s s i f k e d by t h e s e n s e s employed f o r i n t e r a c t i o n
with
database.
the
reviewed
to
at
level.
this
Some
recent
experimental
systems
are
i l l u s t r a t e t h e t y p e of developments t o be expected These
convent&onal query
systems
language
are
contrasted
with
more
systems
2n
a uniform evaluatkon
S e c t i o n 4 d e s c r i b e s t h e low l e v e l
of
the
scheme.
methods l e v e l .
hierarchy,
the
Languages a r e c l a s s i f i e d by t h e methods of query
formulation.
Each
cost-benefit
scheme
method
is
evaluated
based
on
t h e e f f o r t f o r u s i n g t h e system
in
a
(qualitative)
( c o s t ) and t h e f u n c t k o n a l power of t h e language ( b e n e f i t ) .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 6
I n S e c t i o n 5, a language
users
is
evidence from human recommendations
unified
approach
for
developed.
The
results
experkments
factors
classifying
query
of S e c t i o n 4 and
are
used
to
derive
concerning t h e u s a b i l i t y of language methods by
S e c t i o n 6 o f f e r s o u r c o n c l u s i o n s and d i r e c t i o n s
u s e r type.
for
f u t u r e research.
2.
BASIC CONCEPTS AND METHODOLOGY
I n r e c e n t y e a r s , t h e f o c u s of computer systems has
shifted
from nuntber-crunching and mass d a t a p r o c e s s i n g t o t h e management of d a t a a s a s t r a t e g i c r e s o u r c e i n t h e management
systems
provide
o r g a n i z a t i o n , g i v e a v a r i e t y of
a
organization.
conskstent
users
Database
view
appropriate
and
of
the
secure
t o t h e d a t a , and o f f e r e f f i c i e n t f i l e management s u p p o r t
access
f o r a p p l i c a t f o n programs.
A
categorization
of
languages
d a t a b a s e i n t e r a c t i o n s i s p r e s e n t e d i n t h e appendix ( T a b l e 1 ) . c e n t r a l i n t e r a c t B o n mode of u s e r s
with
a
database
system
for A
is
through a query language.
A Query
Roughly,
IQL) cannot
be
defined
preciskon.
it i s a h i g h - l e v e l computer language f o r t h e r e t r f e v a l
of d a t a h e l d i n d a t a b a s e s and f i l e s [BCS 811. focus
with
In t h i s paper
we
on languages f o r q u e r y i n g d a t a b a s e s r a t h e r t h a n a r b i t r a r y
c o l l e c t i o n s of f i l e s .
A q u e r y language i s u s u a l l y assumed t o be
interactive,
and
on-line
ad-hoc { n o t p r e d e f i n e d ) .
able
to
support
q u e r i e s which a r e
I n t e r a c t i o n v i a a QL t e n d s
to
be
of
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 7
low complexity and t h e displayed answer t e n d s t o be 1im2ted t o a I t i s o f t e n assumed t h a t t h e p r i n c i p a l u s e r s of
few l i n e s . are
the
ones'
kmportant
do
performance
contrasted languages
that
with are
usually
usage
usability,
are
tools
is
technical query
efficiency. lkmited
of
expert2se.
development
By
time
construction,
efficiency
in
The as
query
run
time.
t h o s e t h a t s e t pragmatic g o a l s kn terms of
QLs
all-purpose
have
factor
system
Successful and
not
QLs
rather
for
all
production of 10000 m a i l i n g
than
those
t y p e s of u s e r s . labels
in
clakm
that
to
be
For i n s t a n c e , t h e
special
formats
would
r a r e l y be attempted i n a QL.
The taxonomy i s based on our observation t h a t c u r r e n t query languages
have
developers,
developed
originating
from
from
two
the
sources. the
One
areas
of
group
of
programming
languages and database t h e o r y c o n c e n t r a t e s on t h e s y n t a c t i c form and semantic mean2ng of database formal, has
mathematically
moved
restricted
to
oriented
"Engl2sh-lfkes'
natural
interactions.
towards more " u s e r - f r i e n d l i n e s s s ' . developers
started
from
simple
function
The
languages overall
trend
The second group of
with
keys
or
computer
systems.
line-by-line
trend
with
toward
t h e database. more
finally has
been
language
Beginning
prompting,
complex systems i n v o l v e t h e use of menu s e l e c t i o n interaction
and
t h e ergonomic a n a l y s i s o f i n t e r a c t i o n
technology of novice u s e r s with
from
language concepts, t h i s group
keyword
languages.
Starting
or
more
graphical
These developments r e p r e s e n t a
"functionality"
while
remaining
novice-oriented.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 8
I n c o n v e n t i o n a l query languages ( " f i r s t these
two
areas
have
developed
fairly
generation
QLs"),
independently;
s e r v i n g t h e more, t h e o t h e r t h e l e s s s o p h i s t i c a t e d u s e r .
one Recent
developments,
however, l e a d t o an o v e r l a p of t h e usage a r e a f o r
b o t h language
groups.
approaches
to
The
is
challenge
functionally
powerful
r e l a t i v e l y unsophisticated users.
to
integrate
query
languages
both for
We c a l l t h e s e systems "second
generatkon QLsl'.
The upper l e v e l of o u r taxonomy e x p l o r e s i n more d e t a i l t h e differences called
between
senses
QLs.
level
is
interaction
first
and
because
second the
use
It i s
g e n e r a t i o n QLs. of
more
senses
in
one of t h e main advantages i n second g e n e r a t i o n
The lower l e v e l taxonomy f o c u s e s on t h e methods that -
have
been used i n e x i s t f n g , mostly f i r s t g e n e r a t i o n QLs.
Each strengths
of and
the
categories
weaknesses
p r o c e s s of choosing a evaluation
Finally,
which
both
taxonomy
First,
language.
are
established.
determined
t h e multi-dMensional
levels
have
must b e t r a d e d o f f d u r i n g t h e
query
parameters
t h e s e parameters a r e
on
for
the
Next,
each
fmportant
t h e v a l u e s of
language
category.
e v a l u a t i o n c a n be r e l a t e d t o t h e
u s e r and t a s k p r o f k l e of t h e a p p l i c a t i o n t o d e t e r m i n e
the
most
s u i t a b l e query language.
Our e v a l u a t i o n of query languages tables.
For
generating
and
Delphi-like method s e r v i n g a l s o findings.
filling as
a
centers these valTdity
around
several
t a b l e s we used a check
of
our
F i r s t w e made t h e taxonomies of q u e r y languages.
The
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 9
e v a l u a t i o n parameters i n surveying
the
the
literature,
definitions.
agreed
and
reconciling
our
filled-in
the
We
i n d e p e n d e n t l y and had agreement entries.
were
extracting
i m p o r t a n t c o n t r i b u t i o n s , and precise
tables
in
upon
after
generalizing
the
differences
for
table
approximately
entries
90% of
The only c a s e where we had t h e e x a c t o p p o s i t e e n t r i e s
i n a column was caused by a n ambiguous d e f i n i t i o n of t h e heading;
particular
in
language
this
is
paper
i s the 'best'
not
to
important
question
is:
language f o r a c e r t a i n c l a s s survey
what of
psychologically
suggest
that
R a t h e r , we b e l i e v e
f a c t o r s make a QL a b e t t e r
users
and
oriented
applications. studies
of
We query
languages and r e l a t e t h e i r major r e s u l t s and c o n c l u s i o n s t o taxonomy.
our
Although t h e s e r e s u l t s s h o u l d be t a k e n w i t h c a u t i o n ,
we a r e a d v o c a t e s with
a
i n t e r n s of u s e r performance
[LOCBO 76, LOTS 771 o r coverage of f e a t u r e s .
therefore
column
t h e column was s u b s e q u e n t l y dropped.
Our purpose
the
the
of
query languages.
psychologically
oriented
experimentation
Quoting from fSHNEI 781, '...each
result
i s l i k e a s m a l l t i l e c o n t r i b u t i n g t o a n emerging mosaic of behavior...'.
user
One purpose of a taxonomy f o r q u e r y languages i s
t o i d e n t i f y a r e a s where f u r t h e r human
factors
experiments
are
most u r g e n t l y needed.
In t h e n e x t s e c t i o n we begkn o u r h i e r a r c h i c a l presenting
the
highest
level;
languages
are
taxonomy
by
categorized
a c c o r d i n g t o t h e d i f f e r e n t c l u e s and u s e r s e n s e s employed d u r i n g t h e i n t e r a c t i o n of t h e u s e r w i t h t h e system.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 10
THE SENSES LEVEL
3.
The
first
restricted hardware
generation
interaction interface
artificial
query
languages
environment.
[terminal,
The
provide user
keyboard),
and
a
has a l i m i t e d a
relatively
conceptual model of t h e d a t a and t h e i r o r g a n i z a t i o n .
The u s e r a l s o has a formal query language syntax ( t h e the
rules
of
game), and uses h i s experience and mastery of t h e system t o
accomplish h i s t a s k (how t o p l a y and win t h e game). visual
ability
The
they
are
Rather,
Furthermore, t h e u s e r
r e p r e s e n t e d by f o r m a t t e d t e x t .
does n o t employ f u l l y h i s s e n s e s and c o g n i t i o n .
For
instance,
formulation he i s n o t u s i n g v o i c e , touch, h e a r i n g , o r
query
gesture.
user's
while i n t e r a c t i n g with t h e database i s l i m i t e d ;
t h e o b j e c t s of i n t e r e s t a r e r a r e l y d i s p l a y e d d i r e c t l y .
in
very
Additionally,
his
knowledge
of
spatiality
is
not
The u s e r may s t i l l perform h i s t a s k b u t with ljlmited
utilfzed.
p r o d u c t i v i t y and a t t h e expense of more s t r e s s ,
less
interest,
and less p l e a s u r e .
Considerations such a s t h e s e have l e d t o second QL
systems
which
a t t e m p t t o i n c r e m e n t a l l y u t i l i z e t h e human's
i n s t i n c t s and senses. systems basic
Shneidennan [SHNEI 821
a s " d i r e c t manipulation systemsi'. features
reversible
are:
actions,
object
of
of
these
QL
refers
to
these
He states that their
interest
visibility,
rapid
and replacement of command language s y n t a x
by d i r e c t manipulation of o b j e c t s . some
generation
systems
and
In t h i s present
section a
we
review
categorization I n
r e l a t i o n t o f i r s t g e n e r a t i o n QLs.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 11
The emergence of t h e second g e n e r a t i o n query not
coincidental.
-
Hardware New
is
R a t h e r , it has followed and has been g r e a t l y
a s s i s t e d by developments i n many r e l a t e d a r e a s .
(a)
languages
Notably:
Developments
devices
such
as
videodiscs,
content
addressible
memories, h o l o g r a p h i c memories, and o p t i c a l s t o r a g e d e v i c e s allow f o r increased c a p a b i l i t i e s i n s t o r i n g d a t a i n s e v e r a l forms.
use
emergence
of
of
accessing
A d d i t i o n a l l y , v o i c e r e c o g n i z e r s and
s y n t h e s i z e r s , e y e - t r a c k i n g and increased
and
pointing
devices
multi-media i n t e r a c t i o n s .
microprocessor
technology
lead
to
Finally, the
assists
in
the
p r o l i f e r a t i o n of telecommunication networks and d i s t r i b u t e d processing.
( b ) - Developments
2
Graphics ~d
Artificial Intelligence
The a b i l i t y t o d i s p l a y i n f o r m a t i o n i n t h e most n a t u r a l dense
form, t h a t of an image, coupled with h i g h - r e s o l u t i o n
d i s p l a y d e v i c e s and t h e u s e of c o l o r , to
imediate
the
direct
comprehension
representation
interest
[NeSp 79,
processing,
and
-
of
greatly
of
MOORH 761.
objects
of
Research
in
particularly i n natural
e x p e r t systems and r o b o t i c s
f o r m u l a t i o n and u s e r feedback [GaPa 8 Q l . generation
contributes
query o u t p u t and t h e
manipulation
FoVD 8 2 ,
a r t i f i c i a l intelligence
second
and
-
language
a s s i s t s i n query In
general,
the
QL systems a p p e a r more " i n t e l l i g e n t " t o
t h e user.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 12
Ic )
-
&
Developments
Psychology
Related Sciences
I t seems t h e r e i s a new i n t e r e s t i n b r i d g i n g
between
the
gap
t h e r e s e a r c h e r s and p r a c t i t i o n e r s mostly concerned
w i t h t h e human f a c t o r s
aspects
their
are
colleagues
technology
of
tremendous
who
query
query
primarily
language
possibilities
of
concerned
design.
for
languages,
Because
interaction
with
and
with the of
the
second
g e n e r a t i o n query languages, t h e need f o r s c i e n t i f i c methods to
deal
w i t h t h e complex c o n d i d e r a t i o n s of 'convenfence',
'friendLiness\ apparent.
and
Several
"efectiveness'
of
QLs
becomes
p s y c h o l o g i c a l s t u d i e s of QLs have been
r e c e n t l y r e p o r t e d [BrSh 78, REISN 75,81, SHNEI 78, WeSt 811 and
considerable
interest
has
been
generated
i n human
f a c t o r s of query languages a s evidenced by new p r o f e s s i o n a l meetings
and
special
i s s u e s of academic computer s c i e n c e
and p r o f e s s i o n a l p u b l i c a t i o n s f o c u s i n g on human f a c t o r s .
Id)- Success
Computer Games
Computer games have r e v o l u t i o n i z e d t h e way p e o p l e interfaces
to
computer
systems.
The p l e a s a n t and s i m p l e
i n t e r a c t i o n h a s helped remove many that
humans
Naturally,
have
the
while
success
faced of
perceive
psychological
with
computer
a
barriers
computer system. games
influences
d e s i g n e r s of QLs [MALON 821.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 13
It i s hard t o a c c u r a t e l y i d e n t i f y t h e p e r s o n l s ) r e s p o n s i b l e
for
the
emergence
of
second
g e n e r a t i o n query languages.
seems though, t h a t Negroponte and F i e l d s
deserve
major
It
credit
w i t h t h e p r e s e n t a t i o n a t t h e Conference on Very Large Data Bases [FiNe 761.
They
emphasized
clues predefined According
like
data
that,
attribute
traditional
names,
relationships
in
QLs
attribute
order
to
and
iconic
(how
the
d a t a look l i k e ) .
n a v i g a t i n g through t h e d a t a b a s e t a k e s different
values
and data.
EFiNe 761, t h e next s t e p i s t o go beyond symbolic
to
is)
only
retrieve
c l u e s t o o t h e r , more n a t u r a l c l u e s , such as s p a t i a l data
use
a
(where
Browsing o r
dLmension;
new
the
very
from t h e one d e s c r i b e d by Bacbman i n h i s T u r i n g Award
l e c t u r e where t h e programmer i s p o r t r a y e d a s a n a v i g a t o r f i n d i n g his
way
through
a
network
structured
s p a t i a l knowledge seems e s p e c i a l l y
organization
research and
significant
The u s e of
among
all
the
There i s ample documentation i n
i n t e r e s t i n g i d e a s i n tFiNe 761. psychological
database.
substantiating
the
power
of
spatial
t h e a b i l i t y of humans t o remember by l o c a t i o n
and appearance EFiNe 761.
A prototype
database
management,
jmplemented currently
by
Chris
include
based
called Herot
on
the
SDMS, at
CCA
principle
has
been
arrangement.
spatial
developed
[Nerot 81, 8 2 1 .
systems the
ECCA
ability
771. to
The
advantages
It
and
is
SDMS
of
the
l o c a t e o b j e c t s of i n t e r e s t by
browsing and zooming, and t h e u s e of i c o n s , c o l o r , and
of
on INGRES [STONE 7 51 w i t h p l a n n e d e x t e n s i o n s
running
t o o t h e r database system
system
highlighting
s u p p o r t s a m u l t i p l i c i t y of d a t a t y p e s :
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 14
v i d e o and v i d e o d i s c Lmages, i l l u s t r a t i o n s , t e x t , and i c o n s which are
direct
functLons.
representations An
of
t h e u n d e r l y i n g computer system
example of t h e l a t t e r [HEROT 821 i s a n i c o n of
a
c l o c k w i t h t h e c o r r e c t time from t h e computer system.
Another system based multi-media
user
query
the
interface
capability
to
same
principles
databases
of
data
for
of
a
a d a t a b a s e by making u s e of v i d e o d i s c
are
presented
to
the
Motion and
still
u s e r , t o g e t h e r with
browsing c a p a b i l i t i e s and s p a t i a l i n f o r m a t i o n . option
on
i s t h a t of McDonald
technology and i n t e r a c t i v e computer g r a p h i c s . pictures
and
The purpose of t h i s p r o j e c t i s t o develop
[McDON 81, 82a, 82bl. a
on
The u s e r has t h e
u s i n g t h e keyboard, a joystick, o r a touch-panel.
v e r y i n t e r e s t i n g f e a t u r e of t h e system i s
the
flexibility
A
the
u s e r has i n p e r s o n a l i z i n g t h e method of q u e r y i n g t h e d a t a b a s e .
McDonald's system r e q u i r e s t h e u s e r t o machine v i a t h r e e s c r e e n s .
interact
with
the
T h i s s i m u l t a n e o u s viewing c a p a b i l i t y
may have some d i s a d v a n t a g e s c o n s i d e r i n g i n e v i t a b l e head movement and
possible
user
u s i n g t h e system difficulties
in
confusion. a
laboratory
order
a r e not very
setting,
McDonald
reports
p r o v i d i n g i n p u t f o r multi-media i n t e r a c t i o n s .
a l s o r e p o r t s t h a t touch-panels, this
In s e v e r a l e a r l y e x p e r i e n c e s i n
keyboard,
i n user preference. convenient
to
use
and
joystFck
She
follow
The o b s e r v a t i o n t h a t j o y s t i c k s contradicts
the
experiences
r e p o r t e d i n [NEROT 821 and t h e f i n d i n g s o f [EnGr 751.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
SECOND GEWRATION QUERY M G U A G E S
BY
LE VIDEO GRAPHIC QUERY FACILITY
keyboard f u n c t i o n keys picking d e v i c e s touch-sensitive screens voice-recognizers gesture-tracking eye-positioning tracking
keyword c o m n d s menus gesture eye-positioning zooming voice browsing by-example form-f i l l i n g touch
screen v o i c e synthesizer c o l o r graphics video-display printer
Lists Tables Forms Templates Icons Color n i g h l i g h t ing Images Sounds o r v o i c e Arrangement Text
keyboard f u n c t i o n keys picking devices
by-example form-filling
screen printer
Templates Tables
keyboard f u n c t i o n keys touch-sensitive screens picking devices
menus browsing pointing touch
screens (multiple) printer video-display color graphics
Tables Icons Color Arrangement
I
I
v o l c e synthe-
Table 2(a):
Taxonomy of Query Languages a t t h e S e n s e s L e v e l
Center for Digital Economy Research Stem School of Business \Vorking Paper IS-82-35
Low-Medium
Low-Med ium
Table 2 ( b ) :
Taxonomy of Query Languages a t t h e S e n s e s Level
Page 17 The only commercially available Query-By-Example model o f data. and
771,
EZLOOF
second
generation
QL
is
which i s based on t h e relational
Relations are represented d i r e c t l y on t h e screen
t h e user moves the cursor f r e e l y along the rows and columns Query formulation i s done
of the tables. examples;
a
natural
education
major contributions and t h e
through
process.
success
the
use
of
We b e l i e v e t h a t t h e
secrets
of
QBE
are
the
"by-example" principle, t h e two-dimensional data representation, and t h e stepwise l e a r n a b i l i t y feature. fact
that
The l a t t e r r e f e r s t o the
a novice can perform something interest2ng i n a very
short t i m e , yet the system provides a l o t expert user.
more
power
for
the
Several psychological studies focusing on QBE w i l l
be discussed i n Sectkon 5 . In Table 2 we
present
an
evaluation
and
comparison
of
second generation QLs with f i r s t generation query languages.
In
addktion, we present t h e evaluation o f example second generation QL SySternS.
The f i r s t part o f Table 2 examines languages the
query
parameters.
formulatiog For
and t h e output
query
d i f f e r e n t media
that
instance, the user
of
formulation
in
terms
interaction we
first
consider
are available t o t h e language user. a
second
of
generation
QL
may
have
the For in
addition t o t h e regular keyboard some pkcking devkces i j o y s t i c k , mouse), a touch s e n s i t i v e screen, a voice more
important
distinction
though
recognizer,
etc.
A
between t h e two generation
languages with respect t o query formulation i s t h e
I
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 18 the
clues
and
senses
which
2nformation from t h e database. greater
use
of
senses
the
user
employs
user
reply.
of
The
and cogn2tion.
much
Output p r e s e n t a t i o n i s system
informs
t h e a c t i o n r e s u l t , and t h e format of t h e system's latter
appearance,
extract
Second generation QLs make
f u r t h e r subdivided i n t o t h e medkum on which t h e the
to
and
refers their
to
the
types
arrangement
of
objects,
that
may
their
facilitate
comprehension of t h e i n t e r a c t i o n .
The second p a r t of Table 2 i s more s u b j e c t i v e d e a l i n g the
d p a m % c s of
languages. user
user
interaction
for
Interaction c h o k e refers
has
in
choos2ng
medium
appropriate
for
the
task
interesting
and
the
challenge
results,
we
be
say
t h e e v a l u a t i o n of t h e
to
the
flexibility
s t y l e of i n t e r a c t i o n ;
interactLon
important
can
the
switched at
to
that
one
the
whether t h e
is
which
more
When t h e k n t e r a c t i o n i s
hand. of
with
interaction the
has
visBbly
QL system provkdes high
gamesmanshkp.
Most f i r s t g e n e r a t i o n QLs h i g h l y depend on database model.
underlying
It B s e s s e n t i a l t h a t t h e u s e r knows whether t h e
underlying d a t a b a s e system and model network [CODAS 7 1I operate.
the
, or
is
relational
[CODD 711,
h i e r a r c h i c a l [ I B N 751 f o r t h e language t o
The u n d e r l y i n g database model 2 s g e n e r a l l y t r a n s p a r e n t
t o t h e second g e n e r a t i o n language u s e r .
The u s e r can make c l e r i c a l , s y n t a c t i c during
the
5nteraction
or
semantic
errors
and t h e p r o b a b i l m o f something going
wrong i s not s u b s t a n t i a l l y d i f f e r e n t f o r t h e two g e n e r a t i o n QLs.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 19
F&ner d i s t k n c t i o n s of e r r o r s a r e d i s c u s s e d i n t h e n e x t s e c t i o n . O n t h e o t h e r hand, t h e
amount
of
traininq
required
for
the
a c q u i s 2 t k o n of t h e a b i l f t y t o complete an i n t e r e s t i n g t a s k seems t o b e lower with second g e n e r a t i o n QLs.
With
the
direct
manipulation
of
objects
in
second
g e n e r a t i o n query languages, t h e amount of u s e r feedback from t h e system i s v e r y high; Most
users
find
the
it
actkon
is
here
instantly
visible.
i m p o r t a n t t o have t h e f e e l i n g of b e i n g i n
c o n t r o l d u r i n g t h e i n t e r a c t i o n with
the
system;
we
find
no
s u b s t a n t i a l d i f f e r e n c e h e r e between t h e two g e n e r a t i o n QLs.
Where second g e n e r a t i o n QLs, status,
have
less
at
least
capabkl&tLes i s
on
g e n e r a t i o n QLs seem t o have an advantage
in
their
current
funct&onality. here
since
First
they
can
cover a b r o a d e r and more d i v e r s e s e t of f u n c t i o n s .
Different requirements.
requests
may
have
different
output
format
The amount of u s e r f l e x i b i l i t y i n c o n t r o l l i n g t h e
format of t h e o u t p u t i s c a p t u r e d
by
the
user
output
control
parameter.
In summary, second g e n e r a t i o n QLs have over
several
t r a d k t f o n a l f k r s t g e n e r a t i o n query languages:
advantages t h e methods
t h a t t h e u s e r employs i n query f o r m u l a t i o n and comprehension
of
t h e r e p l y , t h e amount of t r a i n i n g r e q u i r e d , t h e system feedback, and t h e gb%esmanship of t h e i n t e r a c t 3 o n .
A d i s a d v a n t a g e may
be
t h e l i m i t e d language coverage.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 20
A word of c a u t i o n i s needed.
a
new
burden
Second generation QLs prov2de
of r e s p o n s i b i l i t y f o r t h e applicat2on developer.
For i n s t a n c e , t h e a p p r o p r i a t e i c o n s t o
represent
use of c o l o r and h i g h l r g h t i n g , and t h e ' n a t u r a l '
objects,
the
arrangements of
t h e o b j e c t s i n t h e database g r e a t l y i n f l u e n c e t h e success of t h e system.
Additional
designers.
These
skills
new
may
skills
be
are
needed not
for
found
application
today
in
the
t r a d k t i o n a l systems analysks and deskgn education.
Furthermore, t h e f a c t t h a t t h e query part,
although
a
language
is
only
c e n t r a l one, of t h e " t o t a l " i n t e r f a c e should
n o t be overlooked.
In a l a y e r of s e v e r a l computer
systems
t h e second generation QL i s t h e outmost l a y e r .
languages
a
and
Apart
from t h e obvious overhead, t h e r e i s t h e g r e a t r i s k of f a l l i n g t o a
lower l e v e l system during t h e i n t e r a c t i o n .
It i s very l i k e l y
t h a t t h e i n t e r a c t i o n with such a lower l e v e l system w i l l n o t consistent
with
protection
mechanisms
interaction
the
level
second
to
for
a
another
generation smooth
QL.
be
We b e l i e v e t h a t
transition
from
one
i s a s t r o n g requirement f o r t h e
s u c c e s s of second generation query language systems.
4.
THE METHODS LEVEL
The languages
previous
section
accordkng
to
generatkon
query
a
taxonomy
of
query
t h e c l u e s and t h e u s e r s e n s e s t h a t a r e
employed f o r t h e i n t e r a c t i o n . first
presented
In t h i s
section,
we
categorize
languages a c c o r d i n g t o method t y p e and
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 21
e v a l u a t e them with r e s p e c t t o i n t e r a c t i o n and
user
parameters.
The t a b l e e n t r i e s
Table 3 summarizes our f i n d i n g s .
performance
and h i g h l i g t s of our comparison a r e now explained.
W e c l a s s i f y t h e f i r s t generation query languages
groups:
functkon-key,
graphic
or
keyword,
pictorial,
positional
a d d i t i o n , we r e l a t e findings
line-by-line
in
restricted
keyword, the
results
eight
prompting, menu s e l e c t & o n , natural
and
in
language,
mathematical
from
this
linear
keyword.
taxonomy
to
In our
t h e s e n s e s l e v e l by grouping t h e second g e n e r a t i o n
QLs ( l a s t row of Table 3 ) .
The use of f u n c t i o n method
i s a ILmited
but
very
of i n t e r a c t i o n f o r inexperienced u s e r s .
effective
By t h e p r e s s of
a s p e c i a l key on t h e keyboard, a p r e v i o u s l y prepared t r a n s a c t i o n or
Is
report
parameterized system-driven
processed.
Line-by-line
ineraction
[LeBl 791,
dialogue.
built-up
a
t h e name
of
the
user's
dialogue
is
responses. menu
A
sjlsnple
the
more
selection.
r e q u i r e d t o p o i n t t o h i s c h o i c e from a menu of by t h e system.
very
f i e l d name, a comparison v a l u e , e t c .
from
system-driven
a
called
I n t h e t y p i c a l c a s e , t h e u s e r w i l l be
prompted t o e n t e r ( l i n e - a t - a - t k n e ) interest,
is
, also
object
of
The query i s sophisticated
Here, t h e u s e r i s options
Menus a r e s t r u c t u r e d h i e r a r c h i c a l l y ;
offered
t h e choice
of a n o p t i o n may cause t h e a v a i l a b i l i t y of a new menu [ElNu 801. These
three
language methodologi!es a r e u s u a l l y custom-made f o r
specific applications.
They may b e based on a lower l e v e l query
language.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 22
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 23
In graphic manipulate
or
visual
pictorial symbols
query
EMCDON
the
t o formulate q u e r i e s .
and r e l a t i o n s h i p s i n t h e d a t a b a s e a r e geometric shapes
languages
user
can
The e n t i t i e s
represented
by
specffic
75, TSICH 76, SENKO 78, ChFu 791.
The r e s t r i c t e d n a t u r a l language mode has a t t r a c t e d i n t e r e s t in
r e c e n t years.
The i n t e n t i o n i s t h a t t h e u s e r can employ h i s
n a t i v e n a t u r a l language l e . g . interaction
with
English, German, French) f o r
A t l e a s t one such QL system i s
t h e database.
c o m e r c f a l l y a v a i l a b l e LAIC 82, HARRI 771 and s e v e r a l o t h e r s the
research
laboratory
at
ELEHMA 77, 78, PLATH 76, CODD 74, 78,
Some n a t u r a l language systems w i l l
WALTZ 78, WILKS 771.
the
engage
i n a d i a l o g u e with t h e u s e r t o r e s o l v e any ambiguity i n r e q u e s t s [CODD 781.
We
communication far
from
should in
out
to the
person-person prefix
the
natural
language
a r t QL systems i s s t i l l cornnunfeation;
"restricted".
s i g n i f i c a n t f o r some s e m a n t i c a l l y for
that
a l l such s t a t e - o f - t h e
close
~ u s t i f i c a t i o n of
point
This
restricted
may n o t b e
applications
some t y p e s o f u s e r s [TURNE 82, STOHR 821.
t h a t n a t u r a l language i s a second g e n e r a t i o n
the
and
It may b e argued
QL.
Even
though
n a t u r a l language may become a dominant QL i n t h e f u t u r e , it does n o t meet our c r i t e r i a f o r second g e n e r a t i o n QLs; has
limited
use
of
the user still
methods, i n s t i n c t s and s e n s e s t o i n t e r a c t
with t h e database.
The m a j o r i t y of q u e r y languages f a l l i n t o t h e l i n e a r keyword.
category
of
These languages u t i l i z e s t a t e m e n t s s i m i l a r t o a
p r o g r m i n g language such a s
FORTRAN,
but
more
English-like.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 24 The
commands
have
a
definite
syntax
s p e c i f i c reserved l i s t can be used. linear
keyword
languages
and QUEL [ S T O N E 7 51
are:
and
Some
only words from a
typical
operands
to
of
[ I B M 751 ,
SQL [ D E N N Y 771 , DL/1
to
the
convey
position
replace
ESCHMI 77,TODD 761.
wordy
The succinctness
of
the
command
meaning [BOYCE 753.
keyword languages use t h e precise notation o f formalism
examples
.
Some keyword languages use operators
and
Other
the
mathematical
English-like
expressions
of
mathematlcal
symbols
allow f o r short expression o f powerful operations.
We have included i n t h e
Appendix
a
list
of
example
QL
language systems as well as the methodologies they employ, t h e i r procedurality type and the underlying database model and system. Representative
QLs are
also
presented
i n t h e l a s t column o f
Table 3 .
The query language t y p e s , as defined above, in
terms
of
three
basic
interaction
, and
f o r m u l a g n , language
are
evaluated
parameters:
output presentation.
Query formulation describes the overall e f f o r t o f t h e to
work
with
the
system.
I t
is
further
the
amount
of
n u t
expressing
the
for t h e query expression (e.g.
number o f k e y s t r o k e s ) , t h e type o f errors i n and
user
divided i n t o the
thinking e f f o r t required before the user s t a r t s request,
query
query
formulation
t h e i r handling, and f i n a l l y , t h e t r a i n i n g e f f o r t needed for
t h e interaction.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 2 5
Most query languages impose a s t r i c t p r o t o c o l the
user
[REISN 841
of
keyword-oriented
introduces
languages.
This r e f e r s t o the
u s e r adopts t o e x p r e s s t h e r e q u e s t .
is
higher
languages
which
model
for are
Reisner
t h e n o t i o n of a "model of t h e p r o c e s s of
query w r i t i n g " t h a t u s e r s develop. the
require
This i s e s p e c i a l l y
t o remember s y n t a c t i c c o n s t r u c t s .
characteristic
and
keyword
The
oriented
systm-driven
strategy of t h i s
languages
dialogues
than
for
(,e,g,
menu
selection).
I n p u t r e f e r s t o t h e amount of c l e r i c a l e f f o r t i n e x p r e s s i n g When t h e i n t e r a c t L o n i s v i a a keyboard t h i s may b e
the request.
measured with t h e number
of
keystrokes.
Alternatively,
with
p o i n t i n g d e v i c e s a good measure i s t h e number of p o i n t e d o b j e c t s [LOTS 811.
The c l e a r winners i n t h i s c a t e g o r y a r e f u n c t i o n keys
and menu s e l e c t i o n .
Three
main
formulation:
types
clerical
of
error
(e.9,
may
occur
a
semantic
lfomulation
s y n t a c t i c a l l y c o r r e c t query which does n o t s o l v e t h e t a s k
a t hand).
will
occur
We c o n s i d e r h e r e t h e for
probability
d i f f e r e n t language t y p e s .
that
such
it
has been d e t e c t e d .
occurs,
function key).
the
correction
an
error
Our f i n d i n g s i n d i c a t e t h a t u s e of
f u c t i o n keys r a r e l y r e s u l t s i n any t y p e of error
errors
Furthermore, we a r e
i n t e r e s t e d i n t h e amount of e f f o r t r e q u i r e d t o h a n d l e after
query
t y p o s ) , s y n t a c t i c ( n o t following
t h e c o r r e c t s y n t a x of t h e l a n g u a g e ) , and of
during
effort
errors,
and
if
an
i s small ( p r e s s another
On t h e o t h e r hand, t h e c h a l l e n g f n g i n t e r f a c e
of
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 26 a
second
generatkon
QL
may
result
f o l l o w t h e wrong p a t h while browsing)
i n semantic e r r o r s le.g. for
which
the
handlhg
This i s n o t t h e e a s e w i t h c l e r i c a l o r s y n t a c t i c
e f f o r t i s high.
e r r o r s i n second genaration QLs;
these errors
are
immediately
d e t e c t e d and t h e r e i s a r a p i d r e v e r s k b l e a c t i o n t o c o r r e c t them.
The amount of t r a i n i n g necessary f o r t h e u s e r level
where
he
consideration training
can
for
2nto
perform
language
to
reach
a
u s e f u l t a s k s i s a very fmportant acceptance.
three categories:
We
have
subdivided
u s e r t y p e l e v e l , composition,
and comprehension.
The u s e r type l e v e l r e f e r s t o t h e degree of user
must
have
before
he
can
use
corresponds t o novice u s e r , medium l e v e l high
expertise
t h e language. to
skilled
Low l e v e l user
and
l e v e l corresponds t o p r o f e s s i o n a l u s e r ( s e e a l s o Sectkon 5
f o r detailed have
an
definitions).
edge
here;
since
System-driven the
user
is
dialogue
languages
guided
durfng t h e
i n t e r a c t i o n , t e c h n i c a l e x p e r t i s e i s n o t necessary. that
the
the
W e a l s o note
u s e r s of r e s t r i c t e d n a t u r a l language must be s k i l l e d ,
a t l e a s t with r e g a r d t o t h e a p p l i c a t i o n domain.
Composition i s t h e t a s k of f o r m u l a t i n g a query.
is
that
A facility
easy t o l e a r n f a c i l i t y i s n o t n e c e s s a r i l y easy t o use.
The analogue i s with t h e p r o g r m i n g language BASIC; almost
takes
no tlime t o l e a r n , b u t w r i t i n g a complex program i n BASIC
i s n o t an easy t a s k .
very
it
little
trainfng
experience ETURNE
Second g e n e r a t i o n query languages
require
f o r using t h e available f a c i l i t i e s .
Our
821 i s t h a t t h e " r e s t r i c t i o n s " p a r t i n n a t u r a l
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 27 language
n e c e s s i t a t e s t r a i n i n g f o r query composition.
must be t a u g h t t o use o n l y
the
allowable
unambiguous
The u s e r English
constructs.
Comprehension r e f e r s t o t h e amount of t r a i n i n g r e q u i r e d understand
a query formulated by another user.
t o understand an unambiguous also
It i s very easy
language
statement.
We
c o n j e c t u r e t h a t a u s e r understands e a s i l y a l i n e a r keyword t h i s i s explained from t h e simple syntax and a p p r o p r i a t e
query; keyword with
natural
to
s e l e c t i o n i n such languages.
little
mathematical
On t h e o t h e r hand, a u s e r
background
find
will
it
hard
to
comprehend a query i n a mathematical keyword language.
The second major parameter f o r query language e v a l u a t i o n i s language
-
power
what f a c t o r s t h i s function
keys
how much a u s e r can do with t h e Language and depends
and
menu
on.
selection
s i m p l i c i t y i n query formulation. designed
to
be
powerful,
the
number
has
where to
the
user
of
pay t h e p r i c e f o r
Although such languages can be
t h e y can never reach t h e e x p r e s s i v e After a l l , there are
power of a keyword-type QL. on
is
This
upper
bounds
of f u n c t i o n keys a v a i l a b l e and on t h e number of
a l t e r n a t i v e s t h a t may be s e l e c t e d b e f o r e t h e menu p a t h becomes a labyrinth.
System-driven application general
domain
purpose.
application
query while In
languages keyword
addition,
Ivocabulary)
must
depend
on
the
orLented languages a r e more the
be
heavily
terminology
of
the
defined before a r e s t r i c t e d
n a t u r a l language i s u t i l i z e d .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 28
discussed
As
generation
in
Section 4,
depends
QLs
on
the
usage
of
most
t h e underlying database system and
t h i s i s e s p e c i a l l y t r u e with keyword o r i e n t e d languages.
model;
S e l e c t i v i t y i s t h e a b i l i t y of t h e language u s e r t o as
first
precisely
as
possible
what
data
he
wishes
t o retrieve
The d e s i r a b l e high s e l e c t i v i t y i s u s u a l l y
[LOTS 811.
specify
found
in
keyword t y p e languages and second genaration QLs.
F u n c t i o n a l i t y r e f e r s t o t h e number of d i f f e r e n t language
can be used f o r .
seems t o be generation
the QLs
major
the
A s we p o i n t e d o u t i n s e c t i o n 4 , t h i s
user
(except
tasks
performance
advantage
of
first
f u n c t i o n keys and menu s e l e c t i o n ) over
second generation query languages.
Our t h i r d major presentation.
This
criterion
variation
[the
which
responsiveness
the
flexibility
p r e s e n t a t i o n format and/or devices),
comparison
QL
in
redirecting (how
rapid
output
presented),
is
selecting output
and
to
suited
output
mostly depend on t h e Regardless,
for
the
system
than
output
is
the
have
the
consistent
application). rather
an
alternative
system's r e s p o n s e ) , and customization ( t h e a b i l i t y t o best
output
is
i s subdivided i n t o c o n t r o l l a b i l i t y of t h e
u s e r t o c o n t r o l t h e pace a t format
for
These parameters
the
language
type.
t h e philosophy behind c e r t a i n language groups l e a d s
t o a more n a t u r a l a d a p t a t i o n of a d e s i r a b l e o u t p u t f e a t u r e i n system. than
a
For i n s t a n c e , customization i s e a s i e r i n menu s e l e c t i o n with
a
positional
keyword
language
and
system
responsiveness i s h i g h l y v i s i b l e i n second g e n e r a t i o n QLs.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 29
The c o n t r i b u t i o n of t h i s s e c t i o n i s t h e and
the
presentation
of
usability
and
taxonomy
of
QLs,
interaction features
a c c o r d i n g t o which query language designs can be evaluated.
The
reader
The
may
look
at
Table 3
c o n s t a n t c o s t i s t h e amount of language
can
be used.
a s a cost-benefit training
necessary
from
the
before
the
V a r i a b l e c o s t s a r e t h e e f f o r t s involved
i n f o r m u l a t i n g q u e r i e s and handling e r r o r s . derives
analysis.
language
power
The
user
benefit
and t h e o u t p u t p r e s e n t a t i o n
features.
Not a l l e n t r i e s i n Table 3 a r e s u b j e c t i v e .
For
instance,
t h e f a c t t h a t t h e f u n c t i o n a l i t y of keyword-oriented languages i s high i n comparison t o t h e use of f u n c t i o n keys prompting i s v e r y h a r d t o argue a g a i n s t .
or
line-by-line
On t h e o t h e r hand, f o r
t h e few s u b j e c t i v e e n t r i e s i n Table 3 , such a s u s e r
type
level
and u s e r model of query w r i t i n g complexity, w e remind t h e r e a d e r t h a t t h e methodology we followed ( d e s c r i b e d i n not
have
strong
scientific
validity.
approach may be misleading a s p o i n t e d o u t conjectures approach.
can
be
The in
s e c t i o n 2) "common
does
sense"
[MORAN 811.
Our
t e s t e d u s i n g what Moran c a l l s t h e f e a t u r e s
T h i s r e f e r s t o experiments t o measure t h e
impact
of
language f e a t u r e s on u s e r performance.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 30
5.
U S E R TYPES A N D ---
QUERY LANGUAGES
In t h i s section, we r e l a t e our taxonomy o f query to
the
d i f f e r e n t types
c l a s s i f i c a t i o n scheme o f which
methods
types.
of
users.
query
We
language
languages
develop
users
a
and
unified
recommend
would be most appropriate f o r t h e d i f f e r e n t user
Where possible, we substantiate our position by e x i s t i n g
human
factors
studies or point out areas where further studies
are needed.
Many c r i t e r i a f o r
classifying
users
781 but t h e i r relationships have hardly uses
a
proposed
expand
it
to
elsewhere. can
An
be
diaensions, frequency
been
studied.
[SHNEI
two-dimensional scheme c l a s s i f i e d by syntactic and
semantic knowledge.
them
been
7 4 , C U F F 80, LeBl 7 9 , MORAN 8 1 , S H N E I 8 0 , YORMA 77, ZLOOF
[CODD
801
have
We base our analysis on
include
other
his
approach
c r i t e r i a t h a t have been proposed
analysis o f these c r i t e r i a reveals t h a t derived
from
namely, of
a
system
familiarity
query
but
language
with
with
of
the four ( b i n a r y )
programming
usage,
most
knowledge
concepts, about
the
application, and range o f d i f f e r e n t operations required.
Familiarity
with
programming
concepts
seems
a
better
wording than the often-cited d i s t i n c t i o n between programmers and non-programmers, which inconsistent
may
interpretations
lead
to
different
and
is
not
afraid
of
times
[ C U F F 80, GrWa 7 8 , MORAN 811.
assign "high" f a m i l i a r i t y with programming concepts who
at
computers
to
a
We user
and has acquired logical or
algorithmic problem-solving a b i l i t i e s .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page
Table 4 (a):
(novice u s e r )
(skilled user)
(skilled user)
(professional user)
User t y p e s
31
-
~ n t e r a c t i o nc a p a b i l i t y ( s y n t a c t i c knowledge) a s a f u n c t i o n of f a m i l i a r i t y w i t h p r o g r a m i n g c o n c e p t s a n d f r e q u e n c y o f system usage.
casual user
c l e r i c a l user
s p e c i a l i s t user
Table 4 ( b ) :
User t y p e s
-
T a s k s t r u c t u r e ( s e m a n t i c knowledge) a s a f u n c t i o n o f a p p l i c a t i o n knowledge a n d r a n g e of o p e r a t i o n s .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 32
The
dimension
of
frequency
system
usage
was
first
We demonstrate t h a t t h i s i s one of t h e
i n t r o d u c e d by [LeBl 791.
most Lmportant dimensions by d e r i v i n g from it many of t h e dimensions
appearing
in
the
literature.
Frequency
d e t e r m i n e s d i r e c t l y t h e a c c e p t a b l e amount of t r a i n i n g ; one
wants
justified.
other of
use
t h e more
t o u s e t h e system, t h e g r e a t e r i n i t i a l i n v e s t m e n t i s The
amount
of
training
in
turn
t y p i c a l s k i l l l e v e l a f t e r t h e t r a i n i n g period.
determines
the
We f e e l t h a t t h e
t r a n s i e n t s k i l l l e v e l s d u r i n g t h e t r a i n i n g phase a r e of i n t e r e s t for
q u e r y language s e l e c t i o n o n l y i f t h e frequency of u s e i s s o
low t h a t each u s e of t h e system r e q u i r e s r e l e a r n i n g turnover
of
users
is
extremely
high.
d i s t i n c t i o n between "novice" u s e r ( t a s k : (task:
In
or
this
if
the
way,
the
l e a r n i n g ) and " e x p e r t "
r o u t i n e s k i l l ) made i n EMORAN 811 c a n be reduced t o t h e
frequency
of
'*novicen n o t
usage only
dimension.
We
therefore
use
the
term
f o r new u s e r s b u t a l s o f o r o t h e r i n f r e q u e n t
u s e r s with l i t t l e programming knowledge.
In
combination,
determine system; 4!a)
the
user"
the
two
dimensions
discussed
so
far
a b i l i t y t o t e c h n i c a l l y i n t e r a c t with t h e
h i s o r her "syntactic
knowledge"
Table
[SHNEI 801.
shows t h e r e l a t i o n s h i p between t h e two b a s i c disnensions and
t h e l e v e l of i n t e r a c t i o n s k i l l .
The semantic knowledge
dhensions
are
concerned
and r a n g e of o p e r a t i o n s o f t h e u s e r .
c o n t e x t , a p p l i c a t i o n knowledqe measures conceptual
with
model
the
application
In t h e database
precision
of
the
t h e u s e r h a s a b o u t t h e s t r u c t u r e and c o n t e n t s
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 33
of t h e d a t a b a s e . very
T h i s c o n c e p t u a l model
d e t a i l e d t o a general idea.
can
be
wants
to
ask
in
the
from
The o t h e r dimension, r a n g e of
o p e r a t i o n s , d e s c r i b e s how many d i f f e r e n t t y p e s user
anything
language.
dLmensFons g i v e a good p i c t u r e of
the
of
queries
the
these
two
Together, task
structure
of
the
u s e r , a n o t h e r semantic c r i t e r i o n ( T a b l e 4 ( b ) ) .
We now proceed t o r e l a t e t h e twelve u s e r t y p e s
defined
by
combinations of s y n t a c t i c and semantic knowledge t o t h e language methods d i s c u s s e d i n t h e p r e v i o u s s e c t i o n .
Developed u s i n g
the
t e c h n i q u e d e s c r i b e d i n t h e Zntroduction and t h e r e s u l t s of human f a c t o r s s t u d i e s , Table 5 language
gives
an
methods f o r each u s e r t y p e .
ordered
list
of
suitable
Before d i s c u s s % n g T a b l e 5
i n d e t a i l , however, we g i v e a g e n e r a l overview of human
factors
r e s e a r c h on t h e methods l e v e l ,
S i n c e t h e now c l a s s i c experkments of [REISN 751 751,
a
number
of
we
can
[ThGo
l a b o r a t o r y s t u d i e s and f i e l d experiments of
human f a c t o r s i n query languages have been purposes,
and
reported.
For
our
c l a s s i f y t h e s e s t u d i e s a s e i t h e r comparisons
between languages t h a t u s e d i f f e r e n t methods,
or
as
usability
s t u d i e s of c e r t a i n f e a t u r e s w i t h i n a language t y p e .
The f i r s t group of experkments c o n s i s t s of keyword
vs.
keyword vs.
second
generation
comparisons
languages [ThGo 75, GrWa 781,
p o s i t i o n a l languages [REISN 751,
and
keyword
r e s t r i c t e d n a t u r a l languages [SHNEI 78, SmWe 77, TURNE 821. r e a d e r i s c a u t i o n e d , however, t h a t n o t a l l of t h e s e intended
a
general
comparison
of
vs. The
experiments
of methods b u t r a t h e r s p e c i f i c
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 34
comparisons of languages.
Nevertheless, t h e y
give
some
hints
and d i r e c t i o n s f o r f u t u r e r e s e a r c h .
The
second
usability
of
given method. been
the
group
certain
of
experiments
languages
One f o c a l p o i n t
keyword
language
concentrates
on
the
o r language f e a t u r e s w i t h i n a
of
laboratory
experiments
has
[REISN77, West 8 1 , WELTY 79,
SQL
THOMA 761, a n o t h e r t h e i n f l u e n c e of conceptual d a t a models [BrSh 78,
LOTS 781.
I n a d d i t i o n , t h e r e have been a number of f i e l d
s t u d i e s concerned languages
in
with
the
various
usability
settings
of
restrPcted
natural
[RAMER79, HARRI 77, KRAUS 79,
LEHMA 78, TURNE 82, WOODS 721.
A s f o r u s e r t y p e s , most s t u d i e s i n t h e s y n t a c t i c
dimension
focus
toward
laboratory
experiments
Therefore,
as
In
chose
subjects
often
contrasting
overall
learn2ng
addition,
with
user. and
Virtually
retention
all
tests.
most
experimenters
explfcitly
l i t t l e knowledge of programming c o n c e p t s ,
them
background.
better
are
novfce
mentioned above, t h e r e s u l t s a p p l y mainly t o t h e
infrequent user.
programming
the
knowledge
with
another
havPng
group
more
A l l experiments of t h k s d e s i g n show a n
performance
for
users
with
programming
background.
The semantic c l a s s i f i c a t i o n of e x p e r i m e n t a l u s e r s clear.
While
the
laboratory
experiments
mostly
is
less
work
with
s t u d e n t s whose semantic knowledge i s d i f f i c u l t t o e s t a b l T s h , t h e thrust
of
the
field
experiments
is
toward
the application
s p e c i a l i s t , l e s s o f t e n toward t h e managerkaf u s e r .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
P a g e 35
line-by-line
menu se 1e c t i o n restricted
line-by-1 i n e
menu s e l e c t i o n
line-by-line
menu s e l e c t i o n
second g e n e r a t i o n
Professions
second g e n e r a t i o n
T a b l e 5:
R e l a t i n g l a n g u a g e methods t o u s e r t y p e s
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Page 36
n-programmers
Table 6:
Human p a c t o r s E x p e r i m e n t s w i t h Query Languages and F e a t u r e s
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 37
The major r e s u l t s of s t u d 3 e s r e f e r r e d t o i n t h i s paper displayed
in
Table
For
6.
a
more
detailed
are
overview
of
l a b o r a t o r y experiments, s e e [REISN 811 o r [SHNEI 8 0 1 .
We now t u r n given
in
to
discussing
the
specifkc
recommendations
Table 5 f o r asskgning language methods t o u s e r t y p e s .
Our procedure w i l l be t o f o l l o w t h e columns
of
the
table
and
t h e n summarize t h e r e s u l t s by language type.
The c a s u a l u s e r i s c h a r a c t e r 2 z e d a s having o n l y
a
general
i d e a about s t r u c t u r e and c o n t e n t of t h e database b u t whose range of needed operatlions 2 s a l s o l j m i t e d s o t h a t he may n o t use f u l l power of a query language [REISN 771. t h e u s e r s of e x t e r n a l electronFc
funds
databases
like
t r a n s f e r systems.
the
Typhcal examples a r e [LOTS 821
videotex
or
Casual u s e r s would o n l y by
chance be f a m i l i a r with programnhg concepts ( t h a t i s t h e reason why
the
lower
f f e l d of Table 5 i s n e a r l y empty) b u t may
left
v a r y kn t h e i r frequency of system usage. the
infrequent
casual
user
c h o i c e s o r line-by-line (skilled)
may
wish
The system must
I n o v r c e ) , by o f f e r f n g skmple menu
prompts, whlile t h e to
adopt
a
more
more
frequent
active
(second
of
actions
.
The managerial u s e r i s probably type.
Unw2lling
user
role
g e n e r a t i o n languages) o r a t l e a s t a f a s t e r sequence ( u s e of f u n c t i o n keys)
guAde
the
most
demanding
user
t o "waste" t h e t o a c q u i r e d e t a i l e d knowledge
of t h e database, he s t i l l wants t o perform q u i t e complicated and varied
t a s k s , e.g.,
types.
Today, menu systems can be used
g e n e r a t i n g summary information of d i f f e r e n t for
s2mple
tasks
and
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 38
kntermediaries
must
handle
complex
ones
happens t o have programming background
unless
and
r o u t i n e l y ( p r o f e s s i o n a l manager5al u s e r ) .
uses
t h e manager the
database
A more d i r e c t p a t h t o
t h e database i s t h e g r e a t promise of advanced language such
as
second
concepts
generatkon QLs o r r e s t r i c t e d n a t u r a l language.
S t u d f e s of usage of n a t u r a l language show, however, t h a t users
may
novice
have problems with t h e s y n t a c t i c r e s t r i c t i o n s of t h e
language [TURNE 821 o r t h e semantic r e s t r i c t i o n s of the d a t a b a s e For t h i s reason, r e s t r i c t e d n a t u r a l language i s o n l y
[BrSh 781.
positioned i n t h i r d place f o r
novkce
managerial
users.
Some
f i e l d s t u d i e s i n d i c a t e t h a t more f r e q u e n t u s e r s of t h i s t y p e can adapt t o t h e l i m i t a t i o n s [KRAUS 791.
Similar
to
the
casual
user,
the
clerical
user
(or
parametric u s e r [ZLOOF 781 ) h a s t o perform only a liLmEted number of o p e r a t i o n s on organization data.
the
gives
database, him
improves
computer-oriented languages
or
day-to-day more
integration
in
the
or
menus
with
productivity.
frequent
clerical
system
little
For
the
user,
more
keyword
o r even t h e more c o n c i s e mathematical languages a l l o w
f o r powerful o p e r a t i o n s . in
his
d e t a k l e d knowledge about t h e a v a i l a b l e
The use of f u n c t i o n keys
guidance
but
general ( s e e , e.g.,
Many s t u d i e s e x i s t f o r t h i s u s e r
type
[EmNa 8 1 , HUMAN 8 2 1 ) b u t l i t t l e h a s been
published on t a i l o r i n g query languages t o c l e r i c a l u s e r s .
A s t h e range of operatkons becomes
user
turns
into
an
broader,
the
clerical
applicatlion s p e c i a l i s t u s e r ( w e a v o i d t h e
synonymous " p r o f e s s i o n a l u s e r " because we
assigned
this
tktle
Center for Digital Economy Research Stem School of Business \Vorking Paper IS-82-35
already
to
a
syntactic
category).
This type of u s e r can be
expected t o have d e t a i l e d knowledge of t h e database and wants t o do
many
d i f f e r e n t operations ( d a t a analysis, decision support)
but often
lacks
programming
programming
background.
conventional
While
and query languages mainly support t h e p r o f e s s i o n a l
( f r e q u e n t and programming) a p p l i c a t i o n s p e c i a l i s t , most recent
research
focuses
on
novice
For
example,
human
factors
the
and s k i l l e d u s e r s who a r e
expected t o be a dominant group of computer u s e r s future.
of
studies
in
the
near
indicate
that
novices :
*
have d i f f i c u l t i e s with e x p l i c i t q u a n t i f i c a t i o n [THOMA 761;
*
perform b e t t e r with a r e l a t k o n a l model of d a t a t h a n with a network o r h i e r a r c h y when u s i n g a keyword language embedded i n APL [LOTS 781 ;
*
l e a r n a second g e n e r a t i o n language (QBE) f a s t e r t h a n a keyword language (SQL) of s u i l a r power EThGo 75, GrWA 781;
*
perform b e t t e r on hard q u e r i e s with a more p r o c e d u r a l approach (TABLET vs. SQL) f o r problem-solving i n a keyword language [West 811;
*
can be o f f e r e d a ( c l o s e d ) s u b s e t i n a l a y e r e d language [REISN 771.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 40
S t u d i e s of t h e use of n a t u r a l language i n t e r f a c e s far
have
so
been i n c o n c l u s i v e , probably due t o d i f f e r e n t u s e r t y p e s and
scope of a p p l i c a t i o n . competitive
if
We hypothesize t h a t n a t u r a l
restricted
to
r e l a t i v e l y sLqple o r t a i l o r e d
a
narrow
database
language
domain
structures
is
[WOODS
721,
EHARRI
77,
DAMER 791, o r f r e q u e n t u s e r s who adapt t o t h e l i m i t a t i o n s [LEHMA
78, KRAUS 791.
More novice u s e r s a p p a r e n t l y g e t i n t o t r o u b l e i f
t h e i r knowledge of t h e d a t a b a s e i s l i m i t e d and i f t h e q u a l i t y of t h e o v e r a l l i n t e r f a c e (compare sectLon 2 ) does n o t match t h a t of t h e query language i t s e l f [TURNE 821.
With -proved
somewhat o p t i m i s t i c p r e f e r e n c e f o r r e s t r i c t e d
Systems o u r
natural
language
o v e r keyword Languages i n t h e upper r i g h t f i e l d w i l l become more realistic. formulation
For s k i l l e d u s e r s , n a t u r a l language of
some
queries,
bud
in
offers
general
a
keyword o r
mathematical language with i t s more powerful o p e r a t o r s preferable.
concise
will
be
The i n c l u s i o n of second g e n e r a t i o n languages i n t h e
lower r i g h t box i s due t o t h e i r r a p i d
reversable
actions
that
s u p p o r t e x p l o r a t o r y u s e of t h e d a t a b a s e [SHNEI 821.
W e have reviewed i n some d e t a i l t h e u s a b i l i t y
methods
for
summarizing
each the
user
results
type.
We
conclude
by
language
type.
this An
of
language s e c t i o n by
interesting
p a t t e r n can be observed h e r e .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 41
The p a t t e r n Section 2
of
query
language
development
around
the
lower
right
of
and
positional)
5, t h a t i s , around
Table
s k i l l e d o r p r o f e s s i o n a l u s e r s with d e t a i l e d d a t a b a s e Keyword
languages
have
more
general
languages which i n t u r n may be more task
in
can be observed i n t h e usage d i s t r i b u t i o n of methods.
Formal query languages (keyword, mathematical, center
outlined
structures
such
as
knowledge.
scope t h a n mathematical
efficient
for
specialized
a p p l i c a t i o n programming.
What t h e s e
languages have i n common i s t h e i d e a of f u l l s p e c i f i c a t i o n of an command o r a sequence of commands i n a command
operation
by
language.
N a t u r a l language can be t h o u g h t of a s a n e x t e n s i o n of
this
kind
a
of
(first
language t o be used by less
generation)
sophisticated users.
The o t h e r choosing
from
(technical) a
line
of
development
starts
with
v e r y l i m i t e d s e t of f u n c t i o n s prompted by t h e
system and t h e n g r a d u a l l y e n r i c h i n g
the
set
accomodate more s k i l l e d o r a m b i t i o u s u s e r s .
of
functions
to
I n a s c e n d i n g degree
of s o p h i s t i c a t i o n , t h i s group of methods Fncludes f u n c t i o n keys, line-by-line
prompting,
menus,
and
f i n a l l y second g e n e r a t i o n
languages.
From Table 5, it c a n be seen t h a t t h e h i g h e r l e v e l s of b o t h developments, language,
and,
sophisticated
second to menu
generation a
lesser
languages, r e s t r i c t e d n a t u r a l
degree,
selection,
keyword
overlap
in
languages their
and
usage.
Currently, t h e r e i s competition r a t h e r than cooperation, b u t t h e long-term t r e n d should b e towards i n t e g r a t i o n .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 4 2
CONCLUSIONS
6.
is
The taxonomy developed i n t h i s paper
based
on
a
new
i n t e r p r e t a t i o n of t h e development of d a t a b a s e query languages a s beLng i n f l u e n c e d by t h e a r e a s of programming languages, d a t a b a s e management,
and
human
factors
engineering.
This observation
l e a d s t o a two-level c l a s s i f i c a t i o n of query languages: user
senses
employed,
and
by
the
by
language methods.
the
It was
d e q o n s t r a t e d t h a t t h i s c l a s s i f i c a t i o n can s e r v e a s
a
e v a l u a t i n g query languages i n a s t r u c t u r e d manner.
In addition,
we developed a
comprehensive
classification
scheme
tool
of
for
query
language u s e r s from which most e x i s t i n g u s e r c a t e g o r i z a t i o n s c a n be derived.
The language and u s e r taxonomies t a k e n us
to
make
specific
recomendations
permitted
together
for
relating
language
methods t o u s e r t y p e s and a p p l i c a t i o n s .
Much remains t o be done. experiments
in
We
have
pointed
out
that
t h e f i e l d have been d i r e c t e d towards comparison
a t t h e g e n e r a l methods l e v e l , and t h a t experiments with language systems have n o t been c o n c l u s i v e .
be
natural
P s y c h o l o g i c a l models
of query f o r m u l a t i o n a r e o n l y i n t h e i n i t i a l s t a g e . to
few
There seems
l i t t l e r e s e a r c h on d a t a b a s e usage f o r c l e r i c a l u s e r s and
on t h e long-tern performance of s k i l l e d u s e r s . generation
languages
are
d i f f e r e n t i a t i o n of methods
in
within
too
early
this
Finally, a
group
stage to
be
second for
the
clearly
understandable.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
Page 4 3
Each s i n g l e language t y p e w i l l have problems the
accoisunodating
v a r i e t y of u s e r t y p e s d i s c u s s e d i n t h i s paper.
We e n v i s i o n
f u t u r e query languages t o employ m u l t i p l e i n t e r a c t i o n o r d e r t o have a broader coverage and u s a b i l i t y . b e l f e v e t h a t new users
to
languages
customize
the
will
provide
interaction
to
in
I n a d d i t i o n , we
facilities their
modes
allowing
own needs and
preferences.
Center for Digital Economy Research Stem School of Business \Vorking Paper IS-82-35
Page 44
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[LoCHO 761 LOC~OVS F.H., ~ ~ , "Data Base Management System U s e r Performance V a r i a b l e s " , Ph.D. T h e s i s , Unhversity of Toronto, ( 1 9 7 6 ) . [LOTS 771 1 Lochovsky, F.H., Tsichritzis, D.C., "User Performance Conskderation i n DBMS S e l e c t i o n " , i n Proceedings of ACM SIGMOB, (19771, p. 128-134.
Lochovsky F.H., T s i c h r i t z i s , D.G., " I n t e r a c t i v e Query Languages f o r E x t e r n a l Databases", CSRG T e c h n i c a l Memo, U n i v e r s i t y of Toronto, ( 1981 )
.
[LOTS 821 Lochovsky F.H. , Tsichrktzis, D. C. , "Querying External Databases", NYU Symposium on User I n t e r f a c e s , New York, ( 1 9 8 2 ) . [MUON 821 Malone,T., " H e u r 2 s t i c s f o r Des2gning Enjoyable User I n t e r f a c e s : Proceedings, Human F a c t o r s i n Lessons from Computer G a m e s " , Computer Systems, Gaithensburg, (19821, 63-68. [McDON 751 McDonald, N a n . , "CUPID: A Graphic O r i e n t e d F a c i l h t y f o r I n t e r a c t r o n s with a Database, Memo Support of Non-Programmer Em-M563, Ph.d. T h e s i s , U n i v e r s i t y of C a l i f o r n i a , Berkeley, (1975). [McDON 81 1 McDonald, N.H. , J , P . McNally, "Video Graphic Query F a c i l i t y proceedAngs of t h e ACM SIGMOD/SIGSMAI;L Database Design", Workshop on Databases f o r Small Systems, Orlando, Florzda, October ( 1 9 8 1 ) . [McDON 82al McDonald, N.H., "Video Graphic Query F a c i l i t y " , t o appear i n proceedings of t h e Second I n t e r n a t 2 o n a l Conference on Databases Improving U s a b i l i t y and Responsfveness, J e r u s a l e m , Israel, J u n e , 11982).
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[MCDON 82bl McDonald, N.H., "Multji-Medha Approach t o User I n t e r f a c e " , Proceedings of t h e NYU Symposium on U s e r I n t e r f a c e s , N e w York, May, (1982).
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[McMc 821 McDonald, N O H . , McNally, L.P., "Query Language F e a t u r e A n a l y s i s by U s a b i l k t y " , unpublished paper, U n i v e r s i t y of South F l o r i d a , (1982). [MOORH 761 Moorhead, WIG., "GXRAM-A Relatkonal Data Base I n t e r f a c e f o r Graphics", Tech. Rep. RJ1735, IBM Research Lab, San Jose, (1976). [MORAN 811 T.P.Moran, "Guest E d k t o r ' s I n t r o d u c t i o n : An Applged Psychology of t h e User", ACM Computing Surveys 13 ( 1 9 8 1 ) , 1-12 [MRI 731 System 2000 Reference Manual, MRI System Corp, (1977).
Austkn,
Texas,
[MYLOP 761 Mylopoulos, J., e t a l , "TORUS: A S t e p Towards B r i d g i n g t h e Gap Between Data Bases and t h e Casual User", I n f o r m a t i o n Systems, 2, (19761, 49-64. [NeSp 791 Neman, W.S., S p r o u l l , R.F., Computer Graphics", McGraw-Hill,
"Principles
of
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N e w York, ( 1 9 7 9 ) .
[NICKE 811 R.S.Nickerson, "Why I n t e r a c t k v e Computer Systems a r e Sometisnes not Used by People who mght Benefkt from Them", 1nt.J.Man-Machine S t u d i e s 15 119811, 469-483 [PLATH 761 Plath, W.J., "REQUEST: A N a t u r a l Language Question Answering System", IBM J. Res. Development, v o l . 20, ( 1 9 7 6 ) . [REISN 751 Reisner, P., Languages: 11975).
"Human F a c t o r s E v a l u a t i o n of Two Data Base Query 44, SQUARE and SEQUEL", Proceedings of NCC, Vol.
[REISN 771 R e i s n e r , P., " U s e of Psycholog3.eal E x p e r b e n t a t 2 o n as a n a i d t o Development of Query Language", IEEE T r a n s a c t i o n s of Software Engineerkng, SE-3, 3, ( 1 9 7 7 ) , 218-229 [REISN 811 P.Reksner, A Survey 13-32
"Human F a c t o r s S t u d i e s of Database Query Languages: and Assessment", ACM Computing Surveys 13 ( 1 9 8 1 ) ,
[SCHAU 761 Schauer,U., "Ein System unfagreicher Messdaten", S p r i n g e r , Berlkn, 11976).
zur
PnteraktWen Bearbektung and S p r u t h , (eds.),
Hesselmeir
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[SCHMI771 Schmidt, J . W . , "Some High-level Language C o n s t r u c t s f o r Data of Type R e l a t i o n " , Transacions on Database Systems, 2, 119771, pp.247-261. [SCHU821 Schmandt,C., Hulteen,E.A., "The I n t e l l i g e n t V o i c e - I n t e r a c t k v e Interface", p r o c e e d i n g s of Human f a c t o r s i n Computer Systems, G a i t h e r s b u r g , Md, ( 1 9 8 2 ) . [SENKO781 Senko, M.E., w i t h Lkght (1977).
"DIAM I1 w i t h FORAL LP: Making P o i n t e d Q u e r i e s Pen", Information Process2ng 77, North-Holland,
[SHIPM 81 ] Shipman, "The F u n c t i o n a l Data Model and t h e Data language DAPLEX"', ACM Transact2ons on Database Systems, 6 , 1 , ( 1 9 8 1 ) . [SHNEI 781 Shnekderman, B * , "Improving t h e Human F a c t o r Aspect o f Database I n t e r a c t k o n s " , ACM T r a n s a c t i o n s on Database Systems, 3, ( 1 9 7 8 ) . [SHNEI 801 B.Shneiderman,
"Software Psyckology8', Cambridge/Mass.,
(1980).
[SHNEI 821 B.Shnefderman, "The F u t u r e of I n t e r a c t k v e Systems and t h e Emergence of D i r e c t Manipulation", Proceedings of t h e NYU Symposium on U s e r I n t e r f a c e s " , New York, May, ( 1 9 8 2 ) . [SmWe 771 Small,D.W., and Weldon,L.J., "The E f f i c i e n c y of R e t r i e v i n g Information From Computers Using N a t u r a l and S t r u c t u r e d Query ~ a n g u a g e s " , Rep. SAI-78-6 55dWA, Science Applicat2ons, September, ( 1 9 7 7 ) . [STOHR821 E.A.Stohr, J.A.Turner, Y.Vassiliou, N.H.whLte, "Research kn N a t u r a l Language R e t r h e v a l Systems", 1 5 t h Ann.Hawai.2 I n t .Conf on System S c i e n c e s , Hawaki 1982
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[STONE751 "The Deshgn and Implementation Stonebraker, M e I e t a l , 1, no. INGRES", ACM T r a n s a c t i o n on Database Systems, v o l . September, ( 1 9 7 6 ) .
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[ThGo 751 Thomas, J . C . and Gould, J . D . , "A P s y c h o l o g i c a l Study o f by Example", Proceedfngs o f NCC, Vol. 44, ( 1 9 7 5 ) . [THOMA 761 Thomas, J . C . , " Q u a n t i f k e r s and Quest2ondAsking", IBM Report, RC 5866, T.J.Watson Research L a b o r a t o r y , HeBghts, N.Y., (1976). [THOMA 775 Thomas, J.C.8 "Psychologkcal I s s u e s i n Data i n Proceedings of Third I n t e r n . Conf. Bases, Tokyo, ( 1 9 7 7 ) .
Research Yorktown
Base Management", on Very L a r g e Data
[TODD761 Todd, S.J.P., '*The P e t e r l e e R e l a t i o n a l T e s t V e h i c l e 0verv2eww, IBM Systems J o u r n a l , 1 5 , ( 1 9 7 6 ) . [TSICH 761 Tsichritzis, D.C. , "LSL: A Link and P r o c e e d i n g s o f t h e ACM SIGMOD, Washington,
Query
Selector 11976).
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A
System
Language",
[TURNE821 Turner,J., Jarke,M., Stohr,T, Vassiliou,Y., and White,N., "Using R e s t r i c t e d N a t u r a l Language f o r Data R e t r i e v a l A Fzeld E v a l u a t 2 o n W , P r o c e e d i n g s on NYU Symposkum on U s e r I n t e r f a c e s , New York, May, ( 1 9 8 2 ) . +
[VONGO 741 Von Gohren, G.L., " U s e r E x p e r i e n c e w i t h I n t e g r a t e d Data S t o r e (IDS) ", Data Base Management Systems, Jardine (Ed. ) , North-Holland, ( 1 9 7 4 ) . [WALTZ 781 Waltz,D.L., "An E n g l i s h Language Q u e s t i o n Answering System f o r a L a r g e R e l a t i o n a l Database", Communications o f t h e ACM, 21, (1978). [ WELTY 79 1
Welty, C., "A Comparison of a P r o c e d u r a l and a Non-Procedural Query Language: S y n t a c t i c M e t r i c s and Human F a c t o r s " , Ph.D. D i s s e r t a t i o n , Univ. Of Mass a t Amherst, ( 1 9 7 9 ) . [West 811 Welty, C . , Stemple, D.W., "Human F a c t o r s Comparison of a Procedural and a Non-Procedural Query Language" , ACM T r a s a c t i o n s on Database Systems, ( 1 9 8 1 ) . [WINOG 711 Winograd, TI " P r o c e d u r e s a s a R e p r e s e n t a t i o n of Data i n a Computer Program f o r U n d e r s t a n d i n g N a t u r a l Language", TR-84, MIT, ( 1 9 7 1 ) .
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[WOODS771 "Lunar Rocks i n N a t u r a l E n g l i s h : Explorations i n Woods, W.A., N a t u r a l Language Q u e s t i o n Answering1*, L i n g u i s t i c S t r u c t u r e s ProcessLng, Zampolli ( e d . ) , North-Holland, ( 1 9 7 7 ) . [WOODS 721 Woods, W.A., Kaplan, R.M., and Nash-Webber, B., "The Lunar S c i e n c e s N a t u r a l Language Informaion System", B o l t Beranek and Newman, Cambridge, Mass, J u n e , 11972). [YORMA 771 Yomark, Be, "The ANSI/X~/SPARC/SGDBMS A r c h i t e c t u r e " , The Ansi/Sparc DBMS Model, Jardine, (ed. ) , North-Holland, Amsterdam, (19771, 521. [ZLOOF 771 Zloof , M., "Query By Example: Systems J o u r n a l , 4, ( 1 9 7 7 ) .
A
Data
Base
Language",
IBM
[ZLOOF 781 Z l o o f , M., "Design A s p e c t s of t h e Query-by-Example Data Base Management Language", i n Databases: Improving U s a b i l i t y and Responshveness, Ben S h n e i d e m a n , ( e d . ) , ( 1 9 7 8 ) .
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
APPENDIX
grouping/sort ing report generation
u s u a l l y provided by h o s t language
PASCAL-R
T a b l e 1:
Examples f o r some t y p e s of d a t a b a s e l a n g u a g e s
EX PLANAT ION
A s e l f - c o n t a i n e d language p r o v i d e s a l l t h e n e c e s s a r y c a p a b i l i t i e s f o r performing d a t a b a s e i n t e r a c t i o n s . On t h e o t h e r hand, t h e s y n t a c t i c forms of a q u e r y language can b e enbedded i n a p r o g r a m i n g language l i k e , PC/I, COBOL, o r PASCAL. There a r e f o u r t e c h n i q u e s f o r embedding (LaPi 8 0 ) : s u b r o u t i n e c a l l s ( D L / I , TOTAL-IQ), s i m p l e e x t e n s i o n (COBOL/DML), nonp r o c e d u r a l o p e r a t o r s (C/QUEL, APL/EDBS) , and i n t e g r a t e d (PASCAL-R) Same q u e r y languages a r e r e t r i e v a l - o n l y ; t h i s i s t y p i c a l o f r e s t r i c t e d n a t u r a l language systems. More commonly, u p d a t e c a p a b i l i t i e s a r e p r o v i d e d . Data a d m i n i s t r a t i o n i n c l u d e s t h e a b i l i t y t o c r e a t e and modify d a t a b a s e d e s c r i p t i o n s , d e f i n e i n t e g r i t y c o n s t r a i n t s and impose a c c e s s c o n t r o l . More language examples a r e g i v e n i n T a b l e 7 .
.
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35
QUERY LANGUAGES
...................................................... LANGUAGE
DB MODEL
DB SYSTEM
METHOD
d-------------
TYPE
REFERENCE
--------------
--d----------------------------------------------------------
ADACOM ADASCRIPT ALPHA ASI/INQUIRY CONDOR CUPID DAPLEX DATA DISPLAY DEDUCE DRUID EQBE EUF I D FOKAL5P GENIE G IS GPLAN HAMEST IDSQ ILL IMMEDIATE INTELLECT I SBL I(ZF LADDER L INUS LSL LUNAR MODEL 204 NATURAL
h y b r kd hybrid relational hierarch2cal natural relational hybrid network relational network relational network hybrid network hierarchical network network hybrid relational hierarchical natural relational hierarchical natural relational network natural network hybrrd
NOMAD
NUL PLANES/JETS PASCAL-R QBE QBPE QLp QUEL QUERY RAMIS RENDEZVOUS REQUEST SWRDLU SQL SQUARE TQA/REQUEST TORUS TOTAL-IQ UDL USL
network natural relational relational relational network relational hybrid natural network natural relational relational natural natural network hybrid natural
ADABAS ADABAS
-
INS
INGRES INGKES IDMS
-
IDMS IDAMS special DLAWII IDMS IMS special SEED IDS
-
SYS-2000 ADABAS PRTV 1MS IDA/FAM
MRDS LSL special MODEL 204 ADABAS NOMAD
.
ALPHA/
PASCAL-R QBE
-
DMS/I 100 INGRES INRGE special TOTAL special SYSTEN R
-
speckal MINIZ TOTAL
-
SYSTEM R
keyword keyword keyword keyword natural pictorial keyword keyword keyword keyword f ill- i n natural pictorkal keyword keyword keyword keyword keyword keyword keyword natural mathm. keyword natural keyword keyword natural keyword keyword keyword keyword natural mathem. fill-in p2ctorkdl keyword keyword keyword keyword natural keyword keyword keyword posit. natural natural keyword keyword natural
navigation navi g a t i o n calculus non-proc. linguistic
-
.
non-proc navigation calculus navi g a ti o n non-proc
.
A1
-
[GMD 753 [GMD 751 [CODD 71,727 [ IBM 7 51 EBANER 771 [McDON 751 [SHIPM 811 [IDMS 771 [CHANG 761 [IDMS 771 [SCHAU 761 [KAMEN 781 [SENKO 781 [IDMS 771 f IBM 751 [HASEM 775 [IDBS 791 [VONGO 741 [ L a P i 751 [MRI 731 [AIC 821 [TODD 761
navigation navigation navigation navigation navigation non-proc. non-proc. linguistic algebra non-proc
~ I B M xx]
A1
[HENDR 781
.
calculus navigation A1
navigation navigati.on non-proc navigation 41 calculus calculus
.
-
non-prqccalculus non-proe non-proc.
.
A1
navigatkon A1
mappkng mapping lingukstkc A1
.
non-proc non-proc. linguisth
[TSICH [WOODS [CCA [GMD
761 72,771 773 751
[DeHe
761 781 771 771 791
[WALTZ [SCHMI [ZLOOF [ChFu [BENNE [STONE
xxj
751
[CODD 74,781 [CINCO 781 [WINOG 711 [ASTRA 761 [BOYCE 751 [PLATH 761 [MYLOP 761 [CINCO 781 [DATE 801 [LEHMA 77,781
Center for Digital Economy Research Stem School of Business IVorking Paper IS-82-35