Development and Validation of a Composite Learning Index for Cambodian High School Students

This study aimed to develop an instrument for measuring student learning and to establish a learning index for high school students. A sample of 1,619 Cambodian high school students was selected using a stratified random sampling technique. Data were collected through a 56-item questionnaire based on a 5-point Likert scale and were analyzed using various statistical methods including descriptive statistics, content analysis, objectivity analysis, correlation analysis, construct validity (using M-plus), reliability analysis (using the R-package for Windows), and t-test analysis. The instrument consists of two key components: “Learning to Know” and “Learning to Do”, each further broken down into ‘Process’ and ‘Outcome’ elements. Each of these sub-components were represented by three distinct indicators. The instrument demonstrated good content validity with an Item-Objective Congruence (IOC) index ranging between 0.50 and 1.00, and excellent construct validity, supported by a variety of goodness-of-fit indices (CFI = 1.00, TLI = 0.99, SRMSR = 0.01, RMSEA = 0.02). The instrument also showed high internal consistency with reliability coefficients ranging from 0.83 to 0.93. The criterion-related validity was confirmed through known-groups validation. Two methods—criterion-related and norm-related—were used to determine students’ learning index levels. For this study, the norm-related method was chosen. The learning index was categorized into four levels: low (0.000 - 0.062), medium (0.063 - 0.375), relatively high (0.376 - 0.680), and high (0.681 - 1.000). Percentile ranks were also calculated to provide additional context for interpreting the learning indices of Cambodian high school students.