Abstract

• The purpose of this study is to investigate whether using vocabulary exercises is effective or not in Grade Ten students’ reading comprehension. The present study was an experimental study. The design adopted in this study was experimental study: the crossover repeated measure design. The study involved (100) participants who were Grade Ten students of English as a foreign language in Basic Education High School, Yathit selected using the simple random sampling technique. To measure their reading comprehension, three main tests that used only unseen passages were administered: pretest, posttest 1 and posttest 2. In the analysis of data, descriptive statistics, independent samples t test, analysis of covariance (ANCOVA), and paired samples t test were utilized. Independent samples t test was employed to determine whether a significant difference exists between the means of two groups. According to the result, analysis of covariance (ANCOVA) was used to ascertain there were differences in the reading achievement between researched students. The results showed that there were differences in the reading achievement between students who received vocabulary exercise and those who did not. Paired samples t test was used to analyze whether the improvement in the students’ reading achievement by the use of vocabulary exercises exists. According to the results, each group had significant improvement in the reading achievement. It can be concluded that the application of vocabulary exercises can improve Grade Ten students’ reading achievement.