Issues in multi-item scale testing and development using structural equation models.

Employing a structural equation model to evaluate a measurement scale can be challenging, especially for a multidimensional scale that contains many items. We describe two issues that can contribute to the poor fit of such models: the statistical power associated with the test of a large measurement scale; and the degree of correlation between items and factors within the scale. These issues are not well understood, so our purpose is to explain them at an applied level, clarify their practical implications for tests of measurement scales and other large structural equation models, and discuss potential strategies for addressing them.