Development of the Estimation Skills Self-Efficiency Scale for Pre-Service Teachers

Estimation skills matters most for both daily life and mathematics education. Teachers have great responsibilities in helping students acquire estimation skills. In this context, it can be said that investigating the pre-service teachers' sense of efficacy about their estimation skills deems important. In this regard, in this study, it was aimed to develop a reliable and valid scale to determine pre-service teachers' self-efficacy for estimation skills. Accordingly, in this quantitative research, a 40- item draft scale was developed based on literature review and expert opinions. Psychometric properties of the scale was tested on data obtained from 158 pre-service teachers. While developing the scale, exploratory and confirmatory factor analyses, Guttman Split Half and Cronbach Alpha internal consistency coefficients were calculated. As a result of the analyses, the percentage of total variance explained for the scale consisting of 20 items and 4 factors was estimated as 69%. The model-fit-indices obtained from the confirmatory factor analysis were acceptable. Cronbach Alpha internal consistency coefficient value for the entire scale was found.90. As a result of the research, a valid and reliable 5-point Likert-type Estimation Skills Self-Efficacy Scale was developed to measure the pre-service teachers' sense of efficacy about their estimation skills. It is thought that this research will contribute to the relevant literature, considering that there is no scale aimed at measuring the self-efficacy perceptions of pre-service teachers in the related literature.