RESUMO
The present study aims to investigate the effect of teaching Problem Solving in groups on the procrastination of male high school students in the city Larestan. This experimental research has used pretest-posttest with a one-month follow-up and there has been a control group involved. The statistical population of this study includes all of the male high school freshmen of the city Lar. In total, a number of 455 male students filled out the procrastination questionnaire. Among the respondents, 30 students with the highest procrastination score were selected as the samples of this study. The experimental group participated in 8 90-minute sessions and they were taught how to solve problems. On the other hand, the control group was not taught anything in this regard. At the end of all of the eight sessions the pretest was performed. Then, after a month, the questionnaires were distributed among the selected students for a follow up. The statistical data was analyzed using descriptive statistic, analysis of covariance and a second measurement. The results showed that there is a significant difference between the procrastination scores in the posttest after eliminating the effect of the pretest. It can be concluded that teaching both time management and problem solving to students significantly affects their procrastination