|M.Sc Student||Di-Nur Nirit|
|Subject||Examining 10th Grade Students' Conceptions Regarding the|
Mechanism of Natural Selection during the Course
of Instruction - A Case Study
|Department||Department of Education in Science and Technology||Supervisor||Ms. Luli Stern|
Evolution of living organisms is a central scientific theory that explains many different areas of biology. Ideas related to evolution, and in particular the concept of natural selection, can explain everyday life phenomena such as the resistance of bacteria to antibiotics. For these reasons, many scientists and science educators have advocated the teaching of evolution at the high school level, not only for advanced students but for science nonmajors.
Research on student learning, however, repeatedly indicates that evolution is one of the most difficult theories to accept. Studies conducted during the past 25 years indicate that despite relevant instruction, high school and college students have difficulties understanding the notion of natural selection for several reasons.
Several intervention studies that were designed to challenge students’ ideas of natural selection have been reported in the literature. The curricular units used in these studies varied in many ways. Overall, their findings indicate that students can simultaneously maintain scientifically accepted ideas and naïve ideas, despite the fact that these ideas contradict one another.
The objective of the present classroom study was to document and describe students’ ideas regarding the concept of natural selection throughout the course of introducing a newly developed conceptual change-based unit.
The study was carried out with high school “Science for All” students. While natural selection is a desired learning outcome in this curriculum framework, curriculum materials that attempt to address the naïve ideas documented in the literature and that are aimed at this particular student population have not yet been developed.
This study supports the view that conceptual change is dependent on the opportunity to construct and reconstruct individual ideas through the process of dialogic argument. Our findings suggest that the students did not undergo a process of ‘holistic’ conceptual change in which one comprehensive conception is replaced by a new, more persuasive one. In most cases, less dramatic changes took place. These findings support previously reported studies that suggested that different patterns of conceptual restructuring are possible. The inconsistency of responses across the multiple probes that were used, imply that students ideas are neither systematic nor coherent, much as described by diSessa (1993) Instead, students’ knowledge consists of fragments that learners use in an unconscious way in response to a particular situation.
This study has both educational and theoretical implications. Insights gained from our study can provide some suggestions for curriculum development, science teaching, and research.