In school settings, sources of self-efficacy have the potential to directly and indirectly influence performance. The problem of this study is the direct relationship between sources of self-efficacy and achievement. In connection with this problem, the impact of sources of mathematics self-efficacy on high school senior students’ mathematics test and course achievement was investigated. The study consisted of 257 12th-grade high school students. The findings of the study showed that mathematics course and test performance increased, whereas the scores for mastery experience, social persuasions, vicarious experience, and physiological state increased, too. According to the results of the regression analysis on mathematics course achievement, the mastery experience significantly predicted mathematics course performance. It also explained 56% of the total variance in mathematics achievement. On the contrary, mastery experience, social persuasions, and physiological state significantly predicted mathematics test achievement, as well as explained 27% of the total variance in mathematics test achievement. In conclusion, sources of mathematics self-efficacy have effects on both mathematics test and course achievement.

The purpose of this research is to examine the effects of formative assessment practices on students' academic achievement, attitudes towards mathematics, and to investigate their views on formative assessment practices. A 12-week quasi-experimental research design was adopted in the research. The research group consisted of 51 students in the 10 th grade (26 in the experimental group and 25 in the control group) of a high school. Qualitative data were obtained via functions academic test and mathematics attitude scale while a semi-structured interview form was used as a qualitative data collection tool. The quantitative results revealed that the effect of formative assessment practices on students' attitudes towards mathematics and mathematics achievement was statistically significant. According to the qualitative results of the research, formative assessment practices were found to be beneficial in terms of contributing to learning processes and encouraging students to express themselves in the classroom. It is recommended that teachers use formative assessment to support student-centered classrooms in teaching mathematics and to effectively evaluate students' mathematical competence in the learning process.