Washback, defined as the effect of exams on teaching and learning processes, has been analyzed under two main categories: positive and negative washback. Exams with significant outcomes can influence participants, educational policies, classroom practices, schools, educational systems, and society as a whole. Thus, this paper examines the washback effect of high-stakes tests on the high school students’ academic achievement in English lesson. Relational survey research design was used. The sample consisted of 806 high school students, including 416 females, and 390 males. The research aimed to identify differences in participants' achievement levels based on their June 2020 LGS (High School Entrance Exam) exam scores in the English section and compare with scores that the same participants obtained four years later from the same test questions. It was found that students' average scores in the English section of the June 2020 LGS were 48.01 out of 100, but dropped to 39.31 when they were retested four years later. Statistically significant differences favoring the initial LGS exam were observed in both comparisons based on school-type and overall student performance in LGS and LGS-Retest scores. Based on the research findings, it has been determined that the YKS (Higher Education Institutions Examination) exam system and its content exert a strong negative washback effect on students' academic achievement in English.
Anlayici et al. (Sun,) studied this question.