Prior to the actual **data** collection, the situations in the original studies were radically modified and adapted to suit the Iranian context. The modified form of the (DCT) is given to two professors for validation. Their suggestions and observations are well taken into consideration in designing the final form of the (DCT). For further validation, the (DCT) was piloted on six subjects, similar to the main group, not included in the sample to see if the language was comprehensible for EFL learners, and based on their opinion a few changes were made. After this stage, to assign students into two proficiency levels, in one session an English language proficiency test (PET, 2004) including questions in reading and writing was given to the participants. The participants, whose score were between 50 and 65, were considered as intermediate, those whose score were above 65 were considered as upper-intermediate and the students whose score were below 50 were sacked from the study. After a week interval, a DCT was administrated to the selected students in two different groups in their classes at Islamic Azad University, Tabriz branch. The **data** was collected by means of this questionnaire that was administered to about sixty EFL students. The important point that needs to be mentioned here is that while sixty students were asked to do the questionnaire, about fifty questionnaires were returned, and out of fifty, forty of them were analyzed as they included incomplete/ misunderstood responses. Selection of disagreement situations in DCT was based on social factor of relative power. The DCT consists of five scenarios, in which the subjects were expected to disagree with a higher status, three with peers and one with a lower status. The scenarios covered a variety of topics and types of situations to avoid intervening effects of topic selection. The participants were asked to produce appropriate disagreement utterances for a given context of situation in DCT. These contexts were selected as they will think to occur frequently. The students in both groups were given enough time to write their answer to each situation. As English was not the participants' native language, the wording of the questionnaire was kept rather simple to minimize any misunderstanding. In the case of intermediate learners, it was decided that the researcher would be available during the questionnaire administration to provide assistance.