Many clinical and social psychologists need to develop scales to carry out their research. Without adequate training in psychometric methods, they can easily run into difficulty. This article is designed to address some of the more common pitfalls in homogeneous scale construction. Empirical scale development by the criterion-group method is not considered. Suggestions are offered about item writing, answer scale formats, data analysis procedures, and overall scale development strategy. Particular emphasis is placed on the effective use of factor-analytic methods to select items for the scale and to determine its proper location in the hierarchy of factor constructs.