Creating Valid and Effective Measures: Using –optifact- to Create Better Summated Rating Scales

While scales are an integral part of the measurements involved in many research projects, few researchers make the effort to ensure that these scales are valid, reliable, uni-dimensional and consistent with relevant correlates. This presentation outlines how the Stata routine –optifact- can be used to create summated rating scales that are better measures of the concept at issue, yet often require fewer questions. An example using a major Canadian survey is presented to illustrate the potential for better analysis and potentially substantial cost savings in survey research.