Ten-year review of rating scales. I: overview of scale functioning, psychometric properties, and selection.

Objective: As part of the Journal's 10-year Research Update Reviews, a series of articles will be presented on the role of rating scales in child and adolescent psychiatry. The first article in the series summarizes principles underlying scale functioning.

Method: Sources were reviewed regarding testing theory, scale development, variability in scale functioning, psychometric properties, and scale selection. The extracted information was adapted to issues in child and adolescent psychiatry.

Results: Rating scales can make major contributions to understanding youths' needs. They provide easy and efficient measurement of psychopathology and quantify underlying constructs for comparison across youths, time, and applications. Although multiple factors may affect a scale's functioning, these factors can be understood and managed by considering the goals of measurement and basic psychometric principles.

Conclusions: Potential users of rating scales should not blindly assume that a well-known scale will meet the measurement needs for a particular application. Rather, they can relatively easily educate themselves regarding the appropriate use of rating scales. This article provides the background information needed to evaluate scales for intended applications. It will also assist in reviewing the individual scales presented in subsequent articles in this series.