How Do Updated Localized Materials Affect Students’ Study Level and Perceptions in a Discipline-specific English Course?

The present study investigated the effect of updated localized materials on the english language achievement of undergraduate students of political science in their english for specific purposes (esp) courses in iran. sixty-five male and female undergraduate students (19-26 years old) from two universities in iran participated in this study. they were divided into two intact classes consisting of 32 and 33 students, respectively, as the experimental and control group. after ascertaining their homogeneity, conducting the pretest, and doing the treatment, which included exposing the experimental group to authentic updated materials, both groups took the posttest. the results of statistical analysis indicated that the use of localized materials enhanced the achievement scores of the participants in the experimental group significantly. the data was triangulated through an attitude questionnaire and interview. the findings could have pedagogical implications for esp learners and instructors.