Explicit inclusion of topic specific knowledge for teaching and the development of PCK in pre-service science teachers
Date
2014-01-06
Authors
Mavhunga, Madlivane Elizabeth
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Reflection about lessons delivered is a practice widely encouraged in teaching. Reasoning,
particularly about transformation of subject matter knowledge of lessons yet to be taught, is
an internal process and a speciality evident largely in expert teachers. The study investigates
the feasibility of fast-tracking its development in pre-service chemistry teachers. It focuses on
developing this specialty within a specific topic, as a theoretical construct called Topic
Specific PCK (TSPCK). Five knowledge components of TSPCK are identified as the
enablers that transform subject matter knowledge. The components are: (1) students’ prior
knowledge, (2) curricular Saliency, (3) what is difficult to teach (4) representations, including
powerful analogies, and (5) conceptual teaching strategies. These components are identified,
with reference to literature, as aspects specific to the subject matter knowledge of the teacher
and useful in its teachability. A new tool to measure the quality of TSPCK is developed.
The procedure for developing the tool consists of the following steps: (i) confirming the
characteristics of the test items fitting the Topic Specific PCK construct, (ii) production of
test items, (iii) judgment of items, (iv) construction of the instrument (v) piloting and (vi)
validation of the instrument. Care is taken to ensure presentation of multiple evidence and
discussions, addressing the interpretive and arguments as requirements for showing validity
of the construct measured by the instrument. The Topic Specific PCK tool is validated with a
group of 20 practicing teachers. The tool is scored, using a rubric corresponding to the five
components with each being rated on a four point scale, from 1 (Limited) to 4 (Exemplary).
The analysis of the generated scores is done using the Rasch statistical model (Winstep,
version 3.72.3). The reliability indices as indicated by person reliability and item reliability
are found to be high at 0.86 at 0.91, respectively. The persons and item scores reflect
measures well inside the conventionally acceptable range of -2 and +2. A further indicator of
validity of the tool is the empirically calculated hierarchy of test items’ order of difficulty,
found similar to the theoretically predicted pattern for the teacher group. Based on the above
analysis and findings, I regard the tool as valid and reliable. My research design is based on
mixed-methods research (MM). The research strategy takes the form of a case study. The
study is located in a methodology class for final year physical science pre-service teachers.
They formed an experimental group (N=16) for this study. I delivered an intervention,
targeting understanding of transformation of Chemical Equilibrium concepts, using the above
listed five knowledge components. I collected data through a combination of tools, including
the newly designed Topic Specific PCK tool in Chemical Equilibrium, an Achievement tool
and a science teacher Belief tool. Both the Achievement and the Belief tools were adapted
from existing tools, and were thus considered tried and validated. The findings suggest that
the quality of Topic Specific PCK in chemical equilibrium may be improved in pre-service
teachers by the explicit discussion of the knowledge enabling its transformation. They also
suggest that, in the process of discussing aspects of subject matter knowledge related to its
transformation, pre-service teachers improve their conceptual understanding of chemical
equilibrium. Both these improvements were not affected by the shift or lack of shift in
teacher beliefs from teacher-centred towards student-centred practices. I acknowledge the
small size of the sample as a practical limitation to the generalization of the statistical
findings in this study. I suggest that emphasis be placed on the trends displayed, as they are
similar to those obtained from the multiple sources of the qualitative component of the study.
Finally, I recommend that the development of PCK in pre-service teachers be considered in a
topic by topic manner. I urge that the teaching of chemistry topics be explicitly organized in
a format in which pre-service teachers would be expected to reason about them, and
particularly transform them for teaching.
Description
Thesis (Ph.D.)--University of the Witwatersrand, Faculty of Humanities, School of Education, 2012
Keywords
pedagogical content knowledge, topic specific PCK, chemical equilibrium, transformation of subject matter knowledge