the effect of washback on reading comprehension of medical students in english for specific purposes classes

background: testing and teaching are interrelated in education process; using various kinds of tests, teachers are able to anticipate the strong and weak points of learning in students, their progress and their accomplishment. the influence of test on teaching and learning is commonly referred to as washback. testing washback is a twisted concept that becomes even more complex under a various interpretations of the washback phenomenon on teaching and learning. this study aimed to describe the effects of washback on behaviors of students, in the low stakes testing in english for specific purpose (esp) environment in two-fold. methods:  the effects of different formative tests on the medical students’ english reading comprehension was assessed using michigan test.. the  effects of washback on the students’ attitudes toward english reading comprehensionwas measured by the english reading attitudes questionnaire (eraq). data were analyzed by paired t-test, t-test, and mann-whitney u test. results: formative tests did not significantly affect on students’ reading comprehension achievement in an esp environment with (mean =71.77±12.3 for experimental group vs 67.59±10.3 for control group, p>0.05]. but they showed  significant effects on students’ english reading attitudes (mean = 38.05 for experimental group vs 21.67 for control group ; p<0.001). conclusions: findings from this study indicate that although formative tests do not significantly affect students’ reading comprehension achievement in english for specific purpose environment, they have significant effects on students’ english reading attitudes.