تأثير مستوى طول الاختبار في دقة تقدير معلمتي الصعوبة والتمييز باستخدام النموذج ثنائي المعلمة في مبحث الرياضيات للصف الثامن الأساسي
This study aimed to determine the effect of the length of the test on the parameters of discrimination and difficulty of the individual using the two-parameter model, and the study sample consisted of 750 students, where the researcher applied three mathematics tests for the ninth grade, consisting of (60, 45, 30) multiple-choice items Shortened from the long test (60) items. The results showed that there were statistically significant differences when estimating the averages of the individual discrimination parameter due to the difference in the length of the test, that is, the average values of the individual discrimination parameter changed with the change in the length of the test, and to know the difference between the averages of the estimation of the individual discrimination parameter with the difference in the length of the test, it was found after making post comparisons that the differences In favor of the long test (60 items) and the medium length test (45 items), and this is in favor of the long test, and the results of the study also found that there are differences in the arithmetic averages of the estimates of the single difficulty parameter with statistical significance due to the change in the length of the test. That is, the averages of the individual difficulty parameter estimates have changed with the change in the length of the test. In order to find out the difference between the averages of the individual difficulty parameter estimations according to the difference in the length of the test, it was found after conducting the dimensional comparisons that the differences are in favor of the long test (60 items) versus the medium test (45 items) and the short test (30 items). (Published abstract)