Blackwell Publishing Ltd.Oxford, UKBJETBritish Journal of Educational Technology0007-1013British Educational Communications and Technology Agency, 20052005363563566ArticlesColloquiumBritish Journal of Educational Technology
British Journal of Educational Technology
Vol 36 No 3 2005
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Colloquium
Teaching evolution using visual simulations Peter Kokol, Marko Kokol and Dejan Dinevski Peter Kokol and Marko Kokol, University of Maribor. FERI, Laboratory for System Design, Smetanova 17, 2000 Maribor, Slovenia. Email:
[email protected]
Introduction Teaching evolution and natural selection is normally a problematical and complicated task (Lerner, 2000), but promising results were obtained by using modern information technology tools (Edwards & Cohen, 1999). As an alternative, we developed a new interactive learning tool for teaching natural selection and origin of random variations. The tool is based on text-to-picture transformations, where the text represents the DNA of a fictional organism. Thus, basic genetic operators like crossover, mutation, selection, and the influence of the environment can be studied in a simple and user-friendly way. The learning environment The three major characteristics of computerised interactive learning (CIL) are individuality, interactivity, and guidance. CIL tools offer students an individualized learning experience, which is based on the two-way interaction between student and computer system. The interaction, in turn, enables the system to provide feedback to the user, and therefore guides the user through the learning environment at the user’s own speed. The three characteristics mentioned are fundamental reasons why CIL tools often improve learning in many subject areas. Many learners learn more effectively when they are in control of their own learning speed, when they are actively and not passively involved, and when feedback is constantly provided. Our central idea was inspired by the work of Sommerer and Migonneau (1999), but it has been elaborated with the inclusion of environmental constraints and crossover. The visual interactive tool is called Words As Organisms (WAO), and it transforms a source text representing deoxyribonucleic acid into simple creatures consisting of bodies (circles), limbs (ellipses), and feet (arcs) covered by various interior patterns. WAO has a simple and intuitive user interface and provides the following basic functions: 1. generating organisms from the source text; 2. crossbreeding; © British Educational Communications and Technology Agency, 2005. Published by Blackwell Publishing, 9600 Garsington Road, Oxford, OX4 2DQ, UK and 350 Main Street, Malden, MA 02148, USA.
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3. mutation (random or pre-specified); and 4. setting the environmental constraints. It also enables users to visually inspect: 1. 2. 3. 4. 5.
how the small changes in the DNA influence the appearance of the organism; how the complexity of DNA influence the complexity of the organism; the functioning of the crossover; the functioning of the mutation; and the influence of environment constraints.
The tool is implemented under Windows environment and can be run using either the ordinary personal computers or palm computers.
The outline of the WAO algorithm The source text is parsed, character by character, with each character being assigned its numerical ASCII (American Standard Code for Information Interchange) value. The pair of successive values is taken as a basis of the transformational process: the first value is a seed for a random generator, generating a series of numbers representing the parameters for function executing production rules; and the second value is the seed for the second random generator, generating the number of functions and the codes of the functions to be executed. Each function represents one of the production rules. A variety of rules can be used, for example, change colour, draw a body, stretch a body in direction x, and so on. After the random sequences are generated, the function calls are executed, and the whole procedure is repeated until the end of the source text.
Case study To present the WAO tool in more practical terms, we simulated the organism’s DNA with the following beautiful poem written by T. S. Elliot and transformed the poem into the organism shown in Figures 1 and 2. where environmental constraints were set to different parameter values. Endless invention, endless experiment, Brings knowledge of motion, but not of stillness; Knowledge of speech, but not of silence; Knowledge of words, and ignorance of the Word. All our knowledge brings us nearer to our ignorance, all our ignorance brings us nearer to death, but nearness to death no nearer to God. Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information. © British Educational Communications and Technology Agency, 2005.
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Figure 1: Organism generated from the Elliot’s poem, environment constraints are set to average
Figure 2: Organism generated from the Elliot’s poem, environment constraints number of bodies are set to minimal
Conclusion—the empirical study To analyse the usefulness and significance of our tool, we performed an empirical study in Slovenian secondary schools. A random sample consisting of 156 students collaborated in the study. Seventy-six were male and 80 were female, and the age range was from 15 to 17 years. All have same basic theoretical foundations in evolutionary biology. We performed a pretest and after the use of our tool, the posttest. The results are shown in Figure 3. We can see that after the use of the tool the results were much better (statistically significant at the 0.05 level). From the yellow line representing the trend of right answers when using the tool, we can also see the increasing motivation of students, also a sign of tool usefulness. © British Educational Communications and Technology Agency, 2005.
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Figure 3: The results of empirical study. The grey bar represents the results before the test, while the solid bar, the results after the test; the grey line represents the linear trend after the test, while the solid line before the test
References Edwards, D. D. & Cohen, B. A. (1999). Teaching evolution on the web using interactive and collaborative learning initiatives. American Zoologist 39, 309. Lerner, L. S. (2000). Good and bad science in US schools—One-third of US states have unsatisfactory standards for teaching evolution. Nature 407, 287–290. Sommerer, C. & Migonneau, L. (1999). Verbarium and life spacies: creating a visual language by transcoding text into form on the Internet. Proceedings of the 4th AROB Meeting, Oita, Japan.
© British Educational Communications and Technology Agency, 2005.
