GRADUATE TEACHING ASSISTANT FIDELITY OF IMPLEMENTATION IN INTRODUCTORY CHEMISTRY AND PHYSICS LABORATORIES: IMPACT ON SCIENCE PRACTICE PROFICIENCY

Abstract

This study reports the fidelity of implementation of the Argument-Driven Inquiry (ADI) instructional model by graduate teaching assistants (GTAs) in introductory chemistry and introductory physics laboratories at East Carolina University (ECU). The ADI instructional model had been fully implemented in the General Chemistry I and II laboratories for several semesters, whereas General Physics I and II laboratories were observed during the first semester of course-wide implementation. An ADI-specific observation protocol was developed and used to document the facilitation techniques of two GTAs in each course for three investigations during Fall 2018 and Spring 2019. The ADI-specific observation protocol was used to determine if student-centered facilitation techniques, by guiding students through the process, or instructor-centered facilitation techniques (lecturing at the students and providing direct answers to questions) were used by the GTA. The ADI-specific observation protocol revealed that one of the GTAs in General Physics I provided primarily student-centered facilitation techniques while the other GTA provided primarily instructor-centered facilitation techniques during some of the stages of the ADI instructional model throughout the semester. The students' results on a practice-focused end-of-course laboratory practical exam were used to determine proficiency with science practices. There was not a significant difference in the mean scores on the end-of-course practice-focused laboratory practical exam in the General Chemistry I and II and General Physics II sections. These results indicate that for these three courses the facilitation techniques of the GTAs had minimal impact on the students' development of science practices. There was a significant difference in the mean scores by the students in General Physics I laboratories, which suggests that differences in facilitation techniques for this section impacted student proficiency with science practices.