Improving students' understanding and perception of cell theory in school biology using a computer-based instruction simulation program.

A survey by the Kenya National Examination Council (KNEC) revealed that students' academic performance and interest in secondary school biology has been generally poor. This has been attributed to the current methods of instruction and the lack of instructional resources amenable to the study and proper understanding of such complex areas as cell theory. The study reported here assessed the effects of a computer-based instruction simulation (CBIS) program developed for the teaching of school biology, as part of a classroom innovation for science instruction to improve students' understanding and perception of cell theory. This article presents results of an empirical evaluation undertaken over a four-week period with 102 form three students in Nakuru district. Comparisons of the pretest and posttest data of the experimental group ([E.sub.1]) and two control groups (C) and ([E.sub.2]) was used to determine the students learning gains with respect to their understanding and perception of cell theory. An analysis of the results showed that the CBIS program resulted in significant learning gains and better perceptions towards the cell division topic in school biology. In addition to corroborating earlier findings on the effectiveness of the use of educational media and hypermedia to improve students' academic achievement and affective behaviors, the study concludes that the innovation has major implications for improving those areas of science that are difficult to teach and learn using the regular methods and should therefore be integrated into the existing school curriculum.

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The primary educational goal for teaching cell division in school biology is to teach students the location and orientation of chromosomes and chromosomal movement during mitosis and meiosis. But with the lack of conducive learning environments and the employment of ineffective approaches, students understanding of cell division might not be effected (Wekesa, 2003). This could be partly the reason why the Kenya Institute of Education (KIE) report (1999) asserted that a considerable number of secondary school students in Kenya hold inadequate understanding of cell theory and the associated underlying concepts as mitosis, meiosis, chromosomes, and chromatids, even after the conclusion of the instructional process. This should not be so because the topic occupies a central role in the biology curriculum at all levels (KIE, 1999; Wekesa, 2003).

Several authors have identified the factors causing this problem to include the lack of adequate instructional materials and/or poor ineffective teaching methods (Ramorogo & Kiboss, 1997). Furthermore. Kiboss (2002) has singled out the expository approach to be the dominant teaching method commonly used for science instruction in our schools. The expository approach is instruction in which the teacher spends most of the time giving verbal explanations in the form of talk-and-chalk while the students listen and write notes from the chalkboard. Obviously, such inadequate and limited teaching methods tend to negatively affect the learners' views of scientific concepts and associated methods (Kiboss & Ogunniyi, 2003). Unless urgent measures are taken to curb the problem, the poor performance on the subject at the Kenya Certificate of Secondary Education (KCSE) national examination that qualifies students for tertiary and post secondary education, shall continue to persist.

Nevertheless, the use of computer-based instruction simulations (CBIS) that have proven useful for teaching areas of science that are considered difficult or dangerous to teach and learn through the regular methods, could prove beneficial in curbing the problem (Kiboss & Ogunniyi, 2003). The topic may also be improved by the use of CBIS program because the current recommended method of using a squashed young onion root tip or electronic micrographs are incapable of giving it the dynamic nature of the process. It is here that a CBIS instructional program would promote realism by incorporating movement and color. This is because a CBIS program is capable of incorporating a model of a process, phenomenon, or system, giving a description of the state of the model and showing its state of change through time and/or as a result of intentional manipulations (Njoo & De Jong, 1993). Moreover, it is an instructional technique that combines animated color graphics to present the dynamic nature of the process of cell division through a multi-sensory approach. This involves the students in complex study processes that allow them to examine a model in a very explorative and ...