Transcript Bild 1 - University of Calgary

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.
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.
The Presentation…….
 Background
 Research questions
 Mode of inquiry
 Results
 Conclusions
 Implications (for research and teaching)
Background
 We believe that some of these domain
specific problems might be related to the
implicit use of different models when teaching
gene function.
Background – The function of the gene can be described
with the help of different models
The phenomenon of gene function
Different ways of describing
Model 1
Model 2
Model 3
(Justi and Gilbert, 1999)
Background - Problems for a user of a model
 Empirical assesment problems.
 Conceptual assesment problems
(conceptual incoherence within or between
the models).
(Stewart & Rudolph, 2001)
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?
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.
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)
Results – 5 Historical Models of Gene Function
 The Mendelian model
 The Classical model
 The Biochemical–Classical model
 The Neoclassical model
 The Modern model
Results - Historical Models of Gene Function
The Mendelian model
The Biochemical-Classical model
The Classical model
The Neoclassical model
Results - Historical Models of Gene Function
The Modern model
Results – 7 Epistemological Features were found
 The structure and function relation of the gene
 The relation between organisation level and
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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.
Results – The function of the gene can be described
with the help of different models
The phenomenon of gene function
Different ways of describing
Model 1
Model 2
Model 3
(Justi and Gilbert, 1999)
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.
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?
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.
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.
Thanks for Your Attention!
Niklas Gericke
PhD-student in Biology Didactics at
Karlstad University
and the Swedish National Graduate
School in Science and Technology
Education Research, FONTD
Karlstad University
SE-651 88 Karlstad, Sweden
tel. 46-(0)54-7001516
fax 46-(0)54-7001462
email: niklas.gericke@kau
Mariana Hagberg
Associate professor in Biology/Didactics of
Biology at Karlstad University
Senior Director of Teacher Education