Messick Validation on the Simulation Test of National Exam Using Rasch Model

This study aims to validate the test items of the computer-based national exam simulation test subjects of the vocational theory of computer engineering competence and vocational high school networks in Tegal City using the Rasch model with the Messick validation model which includes validity aspects: (1) content, (2) substantive, (3) Structural, (4) External and (5) Consequential. To achieve this goal, this study reveals the quality of items including item suitability, Person-item Map, Person / Item Map, Test Information Functions, Person fit statistics, Collapsed Deviance, Casewise Deviance -Hosmer-Lemeshow, accuracy, sensitivity, specificity, unidimensional, invariance, separation and DIF. Data analysis using software R Program Studio version 4.02. Validation of the construct with Rasch modeling gave the following results: (1) The difficulty level of the items was in the range -2 to 2, (2) There were 40 items that matched the modeling, (3) There were 90.06% of student responses that matched the modeling, (4) There are 3 items that contain DIF. Based on the consideration of all aspects of validity, there are 37 items out of 40 that are suitable for use as test items in the test. The conclusion is that the analysis of the items using the Rasch model in the computer-based national exam simulation test, vocational theory exam subjects are declared valid with good item difficulty level.