Researchers discover what they already knew about validity: The case of the family-of-Origin Scale

This article is concerned with two recnet studies of the Family-of-Origin Scale (FOS), Gavin and Wamboldt (1992) and Ryan, Kawash, Fine, and Powel (1994). The external validity analyses conducted for the FOS in these studies assumed the scale to be a unidemsional measure. The present discussion centers on methodological decisions and interpretive strategies that may have prevented a more complete understanding of the scale's dimensional structure and theoretical meaning. It is concluded that a unidimensional view of the FOS is an oversimplification that is inconsistent with the available data. A case is made for a more comprehensive and technically adequate evaluation of the FOS. Specific suggestions are offered.