Difficulty and Discrimination Indices of Logical-Choice Weight and Confidence Scoring Methods on Chemistry Multiple Choice Test in Nigeria Secondary Schools.

Abstract

This study determined which of the Confidence Scoring Method (CSM) and Logical-choice Weight Method (LWM) of scoring Chemistry objective tests is more reliable and valid. This was with a view in enhancing the Discrimination and Difficulty indices of Chemistry objective test for authentic assessment. The population comprised all Senior Secondary School Students in Osun State. A sample of 280 SSSII Chemistry Students was selected from 14 schools that were selected from the 30 local governments including Modakeke-Ife Area Council in Osun State using multistage sampling technique. The instruments used were Chemistry Multiple-choice Test types A and B (CMTA and CMTB). The 40-items Chemistry multiple-choice test was administered on the students in each school, on two scoring methods group. The students in CSM and LWM were told how they would be scored following their responses to the test items and were accordingly marked and scored. Data collected were analyzed using t-test statistics. Result of the analyses revealed that a significant difference existed between CSM and LWM in the discrimination indices (t = 6.18, p<0.05) with CSM (S = 0.598) better than LWM (S = 0.496). However, there was no significant difference between CSM and LWM in difficulty indices (t =0.06, p>0.05) with CSM (S = 0.768) and LWM (S =0.870). It was concluded that CSM could be used to authentically assess Chemistry student’s performance with a view to identify students with genuine learning difficulties, thereby improving curriculum evaluation and instruction.

Key Words: Discrimination Indices, Difficulty indices, Objective test, Learning Difficulties, Confidence Scoring and Logical-choice Weight.