Abstract:
This study aimed to develop and test a causal model for the effect of self-concept on mathematics skill with motivation as a mediator, and to assess its validity. The model consisted of four latent variables including self-concept, math interest, task-orientated behavior, and mathematics skill. The sample consisted of 450 junior high school students in the second semester of academic year 2018-2019 in Champasak district, Lao PDR, randomly selected by multi-stage sampling. The data were collected with a psychological questionnaire and a math test. Test reliability was examined by Lertap5; data were analyzed by deriving descriptive statistics and undertaking a path analysis using LISREL 8.80. Program The result showed that the causal model was consistent with the empirical data. Model fit index statistics were: relative chi-square = 1.75, GFI = .95, CFI = .98, NFI = .96, NNFI = .97, SRMR = .04, RMSEA = .04. Self-concept had both positive direct and indirect effects on mathematics skill through the mediating of mathematics interest and task-focused behavior which are components of achievement motivation. Self-concept, math interest, and task-focused behavior were found to predict 22 percent of the variance in mathematic skill test scores.