Methodological Considerations in the Refinement of Clinical Assessment Instruments

Instrument refinement refers to any set of procedures designed to improve an instrument's representation of a construct. Though often neglected, it is essential to the development of reliable and valid measures. Five objectives of instrument refinement are proposed: identification of measures' hierarchical or aggregational structure, establishment of internal consistency of undimensional facets of measures, determination of content homogeneity of undimensional facets, inclusion of items that discriminate at the desired level of attribute intensity, and replication of instrument properties on an independent sample. The use of abbreviated scales is not recommended. The refinement of behavioral observation procedures is discussed, and the role of measure refinement in theory development is emphasized.