Toward a construct validation of the Louisiana School Analysis Model Instructional Staff Questionnaire

Abstract

This study assessed the construct validity of the School Analysis Model (SAM) Instructional Staff Questionnaire. Construct validation was necessary for several reasons. First, it has not been possible to obtain evidence of the latent factor structure of this key component of the School Analysis Model (SAM). A factor analysis using data collected with the questionnaire was conducted to assess and identify the underlying factor structure of the instrument. Second, there is no evidence that the constructs measured by the SAM are associated with attributes of school performance further empirical analysis was done to determine if latent constructs contained within the SAM Instructional Staff Questionnaire accounted for a significant proportion of variance in school effectiveness beyond that accounted for by the control variables. The eight-factor solution of the SISQ was found to be the best representation of the data based on factor loadings, scale alpha reliability estimates, conceptual cohesiveness, and number of items retained. Correlation analyses were conducted to assess the relationship between the SISQ latent factors and the control variables. Findings indicated a significant inverse relationship was found to exist between a school's SPS and poverty. Additionally, an inverse relationship was found to exist between a school's SPS and the size of a school. Several of the latent factors exhibited a relationship to the control variables as well as to other latent factors. Hierarchical multiple regression analysis was conducted in order to determine whether a combination of the latent SISQ factors account for a significant proportion of variance in school effectiveness, as measured by the school SPS. Model 1 indicated that the control variables explained approximately 56% of the variance in SPS. Model 2 indicated that the SISQ latent factors increased the proportion of variance explained by 11%. The results of this study indicated that the SISQ scales did not account for a significant proportion of the variance in SPS scores and therefore, there is substantial room for improvement in the SISQ as a measurement instrument. Results suggest that construct validation should be of primary concern in the development of measures used to evaluate and guide school improvement efforts.