The influence of excel modelling professional development on conceptual understanding of periodicity of trigonometric functions

Abstract

Utilising an embedded mixed methods research design, this study investigated the influence of an Excel-based modelling (EBM) teacher professional development on learners’ conceptual understanding (LCU) of periodicity of trigonometric functions. A purposive sample of 11 Namibia Senior Secondary School Certificate, Higher Level (NSSCH) mathematics teachers and their 123 learners from a specific region in Northern Namibia, participated in the study. Large Hedges’ g size effect values ( g  0.8) of EBM teacher professional development on teachers’ TPACK self-efficacy (TSE) were confirmed. The semi-structured learner interviews, analysed using a computer aided qualitative data analysis (CAQDA) tool, established that learners found the EBM instruction to have high impact on their on ceptualisation of periodicity of trigonometric functions. The partial least squares structural equation modelling (PLS-SEM) technique was employed to model the relationships between TPACK constructs and their influence of TPACK on learners’ conceptual understanding of periodicity of trigonometric functions. The results indicated that 66% of TPACK is attributed to teachers’ Technological Content Knowledge (TCK), Technological Pedagogical Knowledge (TPK) and Pedagogical Content Knowledge (PCK). On the other hand, PLS-SEM showed that there was a significant positive relationship between TPACK and LCU, with TPACK accounting for 47% of variation in LCU (p < 0.05). There was, however, a weak correlation between teachers’ TPACK self-efficacy and LCU (r=0.25).