Validation of Final Residency Tests Based on the Classical Model in Medical University of Mashhad (A Case Study Improving Dermatology, Ophthalmology, Obstetrics and Gynecology)

Background: Evaluation of students’ educational progress is one of the main goals of universities. One of the most important means to this end is the final test. In this study, the results of the final residency tests for dermatology, ophthalmology and Gynecology and Obstetrics of Medical University of Mashhad in (Tir 1391) have been examined.
Methods: in this applied study, the population consisted of the answer sheets of residency students of dermatology, ophthalmology and Gynecology and Obstetrics of Medical University of Mashhad. The analysis of 113 answer sheets was performed through the classic model, which includes the credibility, level of difficulty and the coefficient of question determination; by the level of difficulty we mean the ratio of correct answers and by the coefficient of question determination, the two-point correlation of the question with the total score. More often than not, the questions included in the final test are the ones with a satisfactory level of difficulty, compatible with the target group and a remarkable coefficient of determination. The exams which lead to issuing the residency certificate are called summative tests. Such tests depend on questions at either extremes, on the one hand, and the discriminant index of questions, on the other, in the classic model.  
Results: the questions at either extremes were introduced. The vague questions or the ones lacking the discriminant index as well as other incompatible questions were excluded; the rest of the questions were regarded as the basis for decision-making and ranking of the test takers.
Conclusions: 1) the ranking of test takers, being influenced by group changes was studied 2) All the questions of each test are compatible regarding both form and content so that all of them share a common feature 3) The questions were screened out through certain formulae and the final test questions were determined 4) The questions are chosen so as to make the test taker produce an answer rather than to pick an alternative from among others 5) Those questions which were left in the final test reflect a general scientific progress rather than a certain course belonging to that particular science.