Al Ishlah Jurnal Pendidikan
Vol 17, No 4 (2025): DECEMBER 2025

Generalizability Theory Analysis of Local Curriculum Validation Instruments: Item Effects and Rater Consistency

Ruslina Irianty (Universitas Negeri Jakarta)
Rustam A.R Selang (Universitas Negeri Jakarta)
Grace Roselin Situmorang (Universitas Pendidikan Indonesia)
Yetty Supriyati (Universitas Negeri Jakarta)
Ilham Falani (Universitas Negeri Jakarta)



Article Info

Publish Date
30 Dec 2025

Abstract

Validating assessment instruments for local curricula presents unique challenges due to context-specific content and reliance on expert judgment. This study applies Generalizability Theory (GT) to evaluate the reliability of a curriculum validation instrument designed for the Social Studies Local Plants program in Fakfak, Indonesia. A fully crossed GT design was used involving 26 items evaluated by 3 expert validators, yielding 78 observations. Each expert rated all items using a 4-point Likert scale. Variance components were estimated using a linear mixed-effects model with REML, implemented via the lme4 package in R. The analysis revealed that item variance accounted for 98.2% of total score variance (σ² = 291.97), indicating strong item discriminability. Rater variance (0.2%) and item × rater interaction (1.1%) were minimal, demonstrating high inter-rater consistency. The Generalizability Coefficient (G = 0.995) and Dependability Coefficient (Φ = 0.986) exceeded the thresholds for both relative and absolute decision-making. A D-study showed that high reliability (Φ ≥ 0.90) could be maintained with as few as 2 raters and 15 items. The instrument demonstrated excellent reliability and is suitable for evaluating local curriculum validity. Minimal rater-related variance suggests that future improvements should focus on item refinement rather than rater training. These findings support the broader use of GT in educational instrument validation, particularly in context-rich, expert-judged settings.

Copyrights © 2025






Journal Info

Abbrev

alishlah

Publisher

Subject

Education Languange, Linguistic, Communication & Media Mathematics Other

Description

This journal focuses on advancing scholarly research and critical discourse in the field of education. It publishes original research articles that address contemporary issues and emerging trends in curriculum development, instructional practices, learning processes, educational policy, and teacher ...