مقارنة طريقتي ألفا و أوميغا في دقة تقدير الثبات في ضوء عدد الأبعاد و طول الإختبار وحجم العينة استنادا لبيانات مولدة

Abstract EN

This study aims to evaluate the accuracy of reliability coefficient estimation using the cronbach's alpha and omega coefficients using generated data through computerized program according to three independent variables : number of dimensions (one, two, and three), length of the test 10, 30, 60 items, sample size of 50, 100, 250, 500, and 1000.

45 different conditions were generated.

the reliability values were estimated using alpha and omega coefficients.

results of t-test for independent samples indicated that there were no statistically significant difference between the two coefficient estimates of reliability in the case of one-dimension tests with different sample sizes and test-lengths.

the results also indicated statistically significant differences between the reliability estimates of the two coefficients in the case of two-and three-dimension tests with different sample sizes and the lengths of the tests.

results also showed slight difference in standard error of estimation for the two methods according to the study conditions.

thus, the study recommends using the omega estimation coefficient in case of multiple dimensions.