Niklas Gericke & Mariana Hagberg Karlstad University, Sweden

1. Definition of Historical Models of Gene Function and Their Relation to Students’ Understanding of Genetics Niklas Gericke & Mariana Hagberg Karlstad University, Sweden Gericke, N. M., & Hagberg, M.: 2007, 'Definition of historical models of gene function and their relation to students' understanding of genetics'. Science & Education, 16(7-8), 849-881.

2. Background - Genetics is considered as the most difficult topic to learn in biology.(Johnstone and Mahmoud, 1980; Bahar et al., 1999) • Knippels (2002) identified five domain-specific difficulties in a literature review about genetic education research: 1) Domain specific vocabulary and terminology. 2) Mathematical content of genetic tasks. 3) Cytological processes of cell division. 4) Abstract nature due to the sequencing of the biology curriculum. 5) The complex nature of genetics: a macro-micro problem, how to relate concepts and processes from different systematic levels.

3. The Presentation……. • Background • Research questions • Mode of inquiry • Results • Conclusions • Implications (for research and teaching)

4. Background • We believe that some of these domain specific problems might be related to the implicit use of different models when teaching gene function.

5. The phenomenon of gene function Different ways of describing Model 1 Model 2 Model 3 Background – The function of the gene can be described with the help of different models (Justi and Gilbert, 1999)

6. Background -Problems for a user of a model • Empirical assesment problems. • Conceptual assesment problems (conceptual incoherence within or between the models). (Stewart & Rudolph, 2001)

7. Research questions • What major historical models of gene function can be described? • What relations between students’ reported understanding of gene function and the historical models can be identified?

8. Mode of inquiry • An analyses regarding the historical development of the meaning of gene function. • Categorization of different meanings of the descriptions of gene function into main historical models. • Epistemic aspects of the models were related to research about students’ conceptions in genetics.

9. Mode of inquiry – Definition of the Historical Models • Main attribute The gene is the basic biological unit of heredity to which a specific function can be assigned(Cadogan 2000) • Secondary attributes These are referred to as epistemological features (Justi & Gilbert 1999)

10. Results – 5 Historical Models of Gene Function • The Mendelian model • The Classical model • The Biochemical–Classical model • The Neoclassical model • The Modern model

11. Results - Historical Models of Gene Function The Mendelian model The Classicalmodel The Biochemical-Classical model The Neoclassical model

12. Results - Historical Models of Gene Function The Modern model

13. Results – 7 Epistemological Features were found • The structure and function relation of the gene • The relation between organisation level and definition of gene function • The “real” approach to define the function of the gene • The relation between genotype and phenotype • The idealistic versus naturalistic relations in the models • The reduction explanatory problem • The relation between genetic and environmental factors.

14. The phenomenon of gene function Different ways of describing Model 1 Model 2 Model 3 Results – The function of the gene can be described with the help of different models (Justi and Gilbert, 1999)

15. Results - Analysis of how the epistemological features relate to students’ understanding • Parallellism between the epistemological features and students’ reported lack of understanding in genetics. • Students seem often to have conceptions similar to the models in the framework of classical genetics.

16. Conclusions • External consistency problems between the models (and internal within them) could be one reason for students’ reported difficulties learning genetics. → How does this influence (or should influence) teaching and learning genetics?

17. Implications - teaching • Hybrid models – attributes from different historical modells. → the use of hybrid models can cause concept confusion among students (Justi 2000). • By using an embedded ’Nature of Science’ approach with the historical models of gene function it is possible to make explicit the epistemic variation in the subject of genetics.

18. Implications - further research • The historical models and epistemological features will be used as analytical tools for further studies of textbooks and classroom studies about teaching and learning in genetics.

19. Thanks for Your Attention! Niklas GerickePhD-student in Biology Didactics at Karlstad University and the Swedish National Graduate School in Science and Technology Education Research, FONTD Karlstad UniversitySE-651 88 Karlstad, Swedentel. 46-(0)54-7001516fax 46-(0)54-7001462email: niklas.gericke@kau Mariana Hagberg Associate professor in Biology/Didactics of Biology at Karlstad University Senior Director of Teacher Education