Abstract
The purpose of this article is to outline the importance of nonindependence to the design of research studies and interpretation of research results. Nonindependence can influence the validity of research results at any level of analysis (i.e., individual, dyadic, group; Kenny & Judd, 1986). We define specifically what nonindependence is, suggesting some sources of nonindependence based on Kenny and Judd. Additionally, we contrast the issue of nonindependence with what James, Demaree, and Wolf (1984) referred to as within-group agreement. Each approach offers a unique advantage in specific situations. We provide an explanation of the steps involved in the tests of nonindependence and within-group agreement from a practical perspective. Finally, we provide a 2-step process for using both data analytic techniques in individual-, dyadic-, and group-level research.