### Project Description

# Project Brief

The purpose of the study is to develop and test a model, based on Self-Determination Theory (SDT), describing the effects of motivational resources on mathematics performance.The model was tested using data from the Third International Mathematics and Science Study-Revised (1999), or TIMSS-R (1999), on the mathematics performance of eighth-grade students in the USA. The conclusions drawn from the study were consistent with the predictions of SDT. Both structural equation modeling and multilevel path modeling analyses confirmed that intrinsic motivation positively influenced mathematics performance, whereas external regulation negatively influenced mathematics performance. A positive mathematics self-concept significantly affected mathematics performance both directly and indirectly through the mediator of intrinsic motivation. Finally, autonomy support in the classroom significantly affected mathematics performance both directly and indirectly through the mediator of mathematics self-concept.

### Introduction

The major purposes of the present study are as follows:

- Develop a model of the effects of motivational resources (e.g., intrinsic motivation and math self-concept) on math performance and achievement.
- Examine whether math self-concept explains additional and significant variance in math performance after we control for the effect of intrinsic motivation on math performance.
- Examine whether autonomy support in the classroom affects math performance (e.g., plausible value scores) both directly and indirectly through the mediator of math self-concept.

### Methods

We performed structural equation modeling analysis using the statistical program, Mplus (Muthen & Muthen, 1998).

### ANOVA

The conclusions drawn from the study were consistent with the predictions of SDT. First, intrinsic motivation positively affected math performance (β=7.865), whereas external regulation negatively affected math performance (β= -15.196), consistent with the first hypothesis (H1). Math self-concept positively affected math performance (β=11.399), consistent with the second hypothesis (H2). Autonomy support positively affected math self-concept (β=0.072) and math performance (β=1.474), consistent with the third hypothesis (H3). Math self-concept significantly affected math performance through the mediator of intrinsic motivation, consistent with the fourth hypothesis (H4). Finally, autonomy support in the classroom significantly affected math performance through the mediator of math self-concept, consistent with the fifth hypothesis (H5).