Secondary Analysis

Secondary analysis involves the use of existing data, collected for the purposes of a prior study, to pursue a research or evaluation interest distinct from the original study. Although secondary analysis is most commonly used when quantitative data have been collected, qualitative data can also serve for secondary analysis. This strategy is frequently used when large data sets are available, sometimes in the public domain, such as (for example) the Trends in International Mathematics and Science Study data set of student achievement in mathematics in many countries around the world. Other examples are the National Assessment of Educational Progress and the Youth Tobacco Survey. Secondary analysis differs from research syntheses and meta-analyses, which compile and assess the evidence relating to a common construct, topic, or area of practice. Although not a common strategy in evaluation, secondary analysis of existing data can provide answers to some evaluative questions, and occasionally secondary analyses of data collected for a program evaluation may be done. The latter may be in the context of a metaevaluation or simply to corroborate evaluative conclusions or ask new evaluative questions. Secondary analysis is, of course, dependent on the availability of data sets.