ABSTRACT: Beliefs are formed through personal experiences and the interactions that individuals are involved in daily life (Hsieh, 2002). These beliefs can be transformed into attitudes, which in turn affect intentions, and decisions are formed through the intentions that lead to the action (Bauch,1984). The match or mismatch between instructors’ beliefs and practices, between instructors’ cognitions and their authentic practices in the classroom are two main fields of the teaching process (Clark & Peterson, 1986). However, teachers may not always apply what they believe in the classroom. This study aims to reveal the discrepancy between what they believe theoretically and what they do in the classroom. To this end, three instruments were used in this study: (1) classroom observations, (2) semi-structured interviews, and (3) a questionnaire. The
questionnaire was compartmentalized into five sub-parts as follows: 1. Involving students in their learning, 2. Modeling for quality, 3. Giving feedback, 4. Self-assessment to explore frequency of classroom activities employed in the EAP classroom procedure. The researcher observed four ESP classes to see what was actually happening in the instructional setting. Moreover, semi-structured interviews were conducted with each of the four ESP teachers whose classes were observed. Based on the teachers’ responses to the formative assessment questionnaire, it was seen that the teachers employed the formative assessment technique quite frequently. However, the researcher took on the role of a non-participant observer to see how frequently and on what occasion instructors made use of formative assessment techniques during ESP classes. The findings of the study reveal that the beliefs of ESP teachers were not always aligned with their actual practices in formative assessment practice. Semi-structured interviews were conducted regarding the issues that instructors encountered when they started teaching ESP.