Alemu, M.

2 Publications in AERD

Author Publications

Development and Validation of a Test of In-service Science Teachers’ Epistemic Knowledge in Electricity and Magnetism Using Rasch Analysis

By Tarekegn, G.

In physics education, assessments address various forms of scientific knowledge. Most of the existing test instruments emphasise the assessment of content knowledge. These tests fail to measure the epistemic aspects of science. Thus, assessing epistemic knowledge is a theme that demands investigation. This study applies Rasch analysis to help validate an epistemic knowledge test in electricity and magnetism. Each of the initial 30 items represents distinct features of scientific reasoning. The construct dimensions are derived from Kind and Osborne’s framework of Styles of Scientific Reasoning. Based on expert validation, a final 20 items were selected. The test was administered to 156 graduating in-service natural science teachers. Reliability and separation indices, person-item mapping, and principal component analysis using standardised residuals are reported. No meaningful secondary dimension was found in the test data. Invariant properties showed that the test had internal coherence. The Wright Map showed the difficulty of the test to the test takers. The overall fit statistics were within the acceptable range. Along the continuum of item difficulty, there were some notable gaps, where future test items judged to be that level of difficulty could be included. We acknowledge that there may be other reasons for these gaps. © 2020 Southern African Association for Research in Mathematics, Science and Technology Education (SAARMSTE).

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Dialogic Teaching in a Teacher Education College: An Analysis of Teacher Educator and Pre-service Teacher Talk in Physics Classrooms

By Worku, H.

The purpose of this case study was to determine the functions of pre-service teachers’ talk and to explore how the teacher educator supports the development of conceptual understanding in a dialogic classroom setting. The participants in the study were a physics teacher educator who employed dialogic teaching to teach mechanics and 52 third-year pre-service teachers at a college of teacher education in Ethiopia. Data for the study were collected through video-recorded classroom observations of three 90-minute lessons. The Kumpulainen and Wray typology of functions of talk were used to determine the functional categories and their relative frequencies in pre-service teachers’ talk. Mortimer and Scott’s forms of teacher intervention were used to explore the nature of the teacher educator’s support in developing understanding. The findings of the study indicated that the pre-service teachers used their classroom talk for a variety of purposes, mainly for providing responses to the teacher’s questions, describing reasons and expressing disagreements in the group discussion. It was also shown that explanation, questioning, providing examples and illustrations, exploring understanding, clarifying group work activities, and encouraging for justification were among the strategies mainly used by the teacher educator to assist knowledge construction. © 2020 Southern African Association for Research in Mathematics, Science and Technology Education (SAARMSTE).

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