effects of frequent announced parasitology quizzes on the academic achievement.

background: the effect of frequent examinations on the students’ learning has had inconsistent results. this study aimed to assess the effectiveness of fre-quent announced quizzes on the learning of a representative sample of iranian medical students. methods: this experimental study was conducted among 37 fifth semester medical students who had taken the course in protozoology and helminthology, in which the same basic information were provided about different types of pro-tozoa and worms. initially, in the teaching of helminthology, ten routine sessions were handled with lectures and interactive questions and answers. then at the beginning of the protozoology topic in the beginning of all of the next 9 ses-sions, the students were informed that they will have a quiz at the end of each session. at the end of the semester, the total scores of quizzes were compared with the mean final scores of protozoology and helminthology using paired t and repeated measure tests. results: the mean final scores of the protozoology lesson were not significantly different from that of the helminthology (10.45 ± 2.75 vs.11.25 ± 2.56 on the scale of 20, respectively, p =0.13). there was no significant difference in the mean score of the five quizzes compared with the mean final term score of pro-tozoology. the overall mean scores in the helminthology lesson (11.25±2.56), protozoology lesson (10.45±2.75), and the quizzes (9.16 ± 3.55) were signifi-cantly different ( p <0.0001). conclusion: frequent announced quizzes were not effective on increasing the medical students' motivation and learning.