The relationship between mean and difficulty index of multiple choice questions test

Abstract

Abstract
In general, we decide students grades based on the average scores that students have done. When the average score is sometimes higher or lower than the instructors expecting, grades will be also based on the difficulty of the course or the skill of the students in the perspective of individual instructor. This may cause a problem of the accuracy and reliability in grading. This study aims to determine the relationship between average scores obtained by groups of students or mean values and difficulty index or p values of multiple choice question (MCQ) test. A retrospective study has been done by collecting data from 2 different subjects: PR201 and PM 203. The test items were examined and analyzed using a computer program. It was found that the percentage of means and the p-value that has a value between 0.00-1.00 of the tests showed absolutely and statistically significant relationship (R = 1.000) by mean (%) = p x 100. Therefore, the mean value of the total scores can be used to indicate the difficulty of the course. Similarity, p-value can be used to indicate the difficulty of the test.