ERROR ANALYSIS OF CLASS XII STUDENTS OF PUBLIC HIGH SCHOOL 18 MEDAN IN SOLVING OPPORTUNITY PROBLEMS

This study aims to analyze the errors made by students in understanding the material of probability and the factors that cause it. With a qualitative descriptive approach, the subjects of the study were students of class XII of SMA Negeri 8 Medan. Data were collected through tests which were then analyzed through the process of data reduction, data presentation, and drawing conclusions. The results showed that the type of error in writing the final answer (encoding error) dominated with a percentage of 66.66%, followed by process skill errors (process skill) 60.09%, transformation errors (transformation error) 54.28%, errors in understanding questions (understanding errors) 52.38%, and errors in reading questions (reading errors) 20.95%. These errors are caused by students' inability to interpret the questions and the tendency to rush, which results in a lack of accuracy. This study suggests that teachers develop learning methods that emphasize reading and process skills, and involve students in discussions to improve their understanding and skills in solving probability questions.