DEVELOPMENT AND CONTENT VALIDATION OF A CRITICAL THINKING SKILLS ASSESSMENT INSTRUMENT FOR GRADE 8 MATHEMATICS: EVIDENCE FROM MULTIDISCIPLINARY EXPERT JUDGMENT

Abstract

Critical thinking is an important educational goal, but measuring it across younger grades can be more challenging because it is multifaceted and can be demonstrated through content, language, and context. The current study presents the development of the Grade 8 mathematics Critical Thinking Skills Assessment Instrument (CTSAI) and evidence of content validation. This instrument was developed iteratively through construct identification, curriculum mapping, item generation, inter- and multidisciplinary expert review, and quantitative and qualitative analyses of expert feedback. Thirty items were written in three domains of Grade 8 Mathematics: Number Sequences and Patterns, Expansion and Factorization, and Linear Equations and Inequalities. The items were developed to call up five critical thinking processes operationalized for mathematics: interpretation, analysis, inference, evaluation, and self-regulation. Eight independent experts from psychology, mathematics education, English education, educational assessment, education administration, and education assessed each item on a four-point scale for relevance, clarity, grade-level appropriateness, critical-thinking alignment, and curriculum alignment. Item-level and scale-level content validity indices were computed along with a qualitative review of expert comments. The overall S-CVI/Ave was 0.999; all criteria except clarity had an S-CVI/Ave of 1.000, while clarity was 0.9958. There was unanimous consensus on the relevance criterion used in retention decisions for twenty-nine items, and the one item (Item 9) had an I-CVI of 0.875 and was retained with minor word changes. The results offer preliminary test content evidence, but lack evidence of reliability, factor structure, item functioning, and criterion-related validity. Therefore, the CTSAI is a content-valid instrument that needs field testing with Grade 8 students before making claims about broader measurement validity.