Generally, a test is administered to measure students' performance in certain skills and/or topics. Specifically, in formal school, semester tests are conducted as a review to discover students' achievement after learning for six months. This study aimed to analyze the tests constructed by teachers at Junior High Schools in one of the regions in Riau. The focus of this study was item analysis and teachers' factors which affect the effectiveness of the test items. Evaluation research was conducted in order to answer the research questions. The data were taken from four semester tests designed by four different teachers of eight grade of junior high school in the region. Furthermore, an interview was also conducted to the teachers to know teachers' factors that influence the effectiveness of the test items. The results of this study reveal that the test was dominated by moderate items and those items are functioned well. However, most of the items cannot discriminate between high and low students. In addition, it is found that the first teachers' factor significantly affecting the effectiveness of the test items is training on test construction, then followed by teachers' experience in constructing a test. It is expected that the authority could select more experienced teachers to design the tests and frequently facilitate the teachers with training on test construction to enhance teachers' competence in designing tests.