Exploring one aspect of pedagogical content knowledge of teaching assistants using the test of understanding graphs in kinematics

Alexandru Maries,Chandralekha Singh

doi:10.1103/physrevstper.9.020120

Abstract

The Test of Understanding Graphs in Kinematics (TUG-K) is a multiple-choice test developed by Beichner in 1994 to assess students' understanding of kinematics graphs. Many of the items on the TUG-K have strong distractor choices which correspond to students' common difficulties with kinematics graphs. Instruction is unlikely to be effective if instructors do not know the common difficulties of introductory physics students and explicitly take them into account in their instructional design. We evaluate one aspect of the pedagogical content knowledge of first-year physics graduate students enrolled in a teaching assistant training course related to topics covered in the TUG-K. In particular, for each item on the TUG-K, the graduate students were asked to identify which incorrect answer choice they thought would be most commonly selected by introductory physics students if they did not know the correct answer after instruction in relevant concepts. We used the graduate student data and the data from Beichner's original paper for introductory physics students (which was collected from over 500 college and high school students) to assess this aspect of the pedagogical content knowledge of the graduate students, i.e., knowledge of student difficulties related to kinematics graphs as they are revealed by the TUG-K. We find that, although the graduate students, on average, performed better than random guessing at identifying introductory student difficulties on the TUG-K, they did not identify many common difficulties that introductory students have with graphs in kinematics. In addition, we find that the ability of graduate students to identify the difficulties of introductory students is context dependent and that discussions among the graduate students improved their understanding of student difficulties related to kinematics graphs. Moreover, we find that the ability of American graduate students in identifying common student difficulties is comparable with that of foreign graduate students.

Highlights

The Test of Understanding Graphs in Kinematics (TUG-K) [1] is one of many multiple-choice tests designed to assess conceptual understanding in introductory physics [2,3,4,5,6,7,8,9,10,11]
Analysis of the pedagogical content knowledge (PCK) performance of the graduate students was performed on each of the questions on the TUG-K which revealed a moderate or major introductory student difficulty and it is shown in Figs. 1 and 2
The TUG-K related PCK performance of the graduate students on a given question was considered ‘‘good’’ if their normalized average PCK score is 67% or more of the maximum possible score, ‘‘moderate’’ if their normalized average PCK score is between 50% and 67% of the maximum possible score, and ‘‘poor’’ if their normalized average PCK score is less than 50% of the maximum possible score

Summary

Introduction

The Test of Understanding Graphs in Kinematics (TUG-K) [1] is one of many multiple-choice tests designed to assess conceptual understanding in introductory physics [2,3,4,5,6,7,8,9,10,11] Some of these tests, e.g., the Force Concept Inventory [3], have been widely used by instructors and education researchers for various purposes, for example, to identify student difficulties [2,12], to compare the effectiveness of curricula and pedagogies [13], and to investigate gender differences [14,15].

Methods

Results

Conclusion