The aim is of this research to know the effectiveness of cooperative learning STAD type in remediating students' misconceptions about the simple machine at SMP Yakhalusti Pontianak. The method used is experimental in the form of pre experimental designs with the type one-group pretest-posttest design. The subject of the research was IX grade consisting of 34 students. The instrument for collecting data was a multiple-choice test with three alternatives choice and reasons. The analysis data showed that the mean percentage of students' misconceptions before being given the remediation was 92.40% and the mean percentage after being given the remediation was 60.29%, resulting in a decrease in the percentage of students misconceptions after being remediated by 32.11%. The result of the Wilcoxon test showed that there is a significant decrease in students' misconceptions after being given the remediation (α = 5%; ztable = 1,645; zcount = -4,958). Based on the calculation of the price of the proportion of the amount change on students' misconceptions obtained the mean score was 0.36 with the effectivity being moderate. It can be concluded that the use of cooperative learning STAD type is effective in remediating students' misconceptions about the simple machine at SMP Yakhalusti Pontianak.
