A DEVELOPMENT OF A TEST ITEM BANK FOR ENVIRONMENTAL CHEMISTRY FOR TEACHERS APPLYING 4-PARAMETER ITEM RESPONSE THEORY

Abstract

The purpose of this study was to develop a test item bank for environmental chemistry test for teachers using 4-parameter item response theory. The samples obtained by simple random sampling consisted of 200 general science students in the Faculty of Education, Roi Et Rajabhat University, in the academic year 2019. The instrument used in the research was four multiple-choice test. Data was analyzed for test parameters according to item response theory using the Program R packages including Mirt, Lavaan, Psych, and GPArotation packages before selecting the items for the bank.

The results showed that 120 test items qualified from the experts totally 90 items with the index of congruence (IOC) between 0.60-1.00. The items are listed by a parameter value and the item selection criterion to provide discriminatory power (a) between 0.50 to 5.00, item difficulty (d) between -3.00 to 3.00, pseudo-guessing (g) not over 3.00, and slipping effect (u) less than 0.70. There were 18 items which qualified a criterion for the test item bank selection. Item discrimination was between 0.55 to 4.55 with mean score at 1.96 and standard deviation at 1.38, indicating that the exam has relatively high discriminatory power. Item difficulty (d) was between –2.82 to 2.95 with mean score at 1.42 and standard deviation at 1.64 which indicated that the difficulty of the test was moderate and relatively easy.

Pseudo-guessing (g) was between 0.00 to 0.30 with their mean score at 0.06 and standard deviation at 0.01. Slipping effect (u) was between 0.72 to 1.00 with mean score at 0.93 and standard deviation at 0.00. The item bank was conducted by the PhpMyAdmin database program which could store images and texts for further development of a computerized adaptive testing program.