Dynamic assessment (DA) which is rooted in Vygotsky’s (1978) sociocultural theory involves the integration of instruction and assessment in a dialectical way to achieve two main purposes: enhancing learners' development and understanding about their learning potential. However, the feasibility and appropriateness of mediation are two main concerns of DA. The former is concerned with the application of DA for a large number of students, while the latter is concerned with providing test takers with appropriate hints. The purpose of the current study was three-fold: to examine the difference between dynamic and nondynamic tests, to understand about test takers' potential for learning, and to find out how mediation works for high and low ability students. To achieve these aims, computer software was developed. The software is capable of both providing the test takers with graduated hints for each item automatically, and adapting the overall difficulty level of the test to the test takers' proficiency level. To test the efficiency of the software in employing dynamic assessment, 83 Iranian university students participated in the study. The results of the study indicated that the computerized dynamic test made significant contribution both to enhancing students' grammar ability and to obtaining information about their potential for learning. Based on the findings of the study, it can be concluded that the use of dynamic assessment can simultaneously lead to the development of the test takers' ability and provide a more comprehensive picture of learning potential. Accordingly, teachers are recommended to use dynamic assessment to make more informed decisions about their students.
