Estimating the Psychometric Properties (Item Difficulty, Discrimination and Reliability Indices) of Test Items using Kuder-Richardson Approach (KR-20)

Abstract

There is no need or point to testing of knowledge, attributes, traits, behaviours or abilities of an individual if information obtained from the test is inaccurate. However, by and large, it seems the estimation of psychometric properties of test items in classroomshas been completely ignored otherwise dying slowly in most testing environments. In the quest to obtain sound and efficient test results, it is imperative that assessorsrely on somepsychometric properties to make informed classrooms decisions. These psychometric properties can be estimated using Kuder-Richardson20 Formula. In this study, 30 multiple-choice items were administered and used for the study. The strength of each item was analysed by looking at their difficulty level and how theydiscriminated among the students. Reliability tests were also conducted in addition to the item analysis to observe the quality of the test as a whole. With lucid prose, KR-20 was used to estimate the psychometric properties of 30 set integrated science test items (which werescored dichotomously)to serve as a primer for assessorsin higher institutions.The procedure produced coefficient value of 0.6915which is approximately 0.7 implying that the reliability of the test was high.The procedure we used to arrive at the obtained coefficient is extensively outlined in the paper. We concluded thatthe suggested procedure (KR-20) for estimating psychometric properties may have a paradigm shift in classroom testing situations where it will communicate to teachers on the efficiency and process of teachermade tests. In essence, this could enhance the quest of obtaining the real knowledge, attributes, traits, behaviours or abilities of students by using test items that are reliable and dependable.