Tonn, B., and Frederick G. Conrad. 2003. "Using Informants' Judgments to Infer Attributes in Dynamic Domains." Field Methods, 15: 202-217.
This article describes a methodology, called the Product Attribute Characterization Technique (PACT), which is designed to elicit from informants information to group and describe products. The methodology was developed for use by the Bureau of Labor Statistics in price-indexing efforts. Informants are required to complete three tasks: provide a list of products that fall into the area of analysis, group these products on the basis of similarity, and compare and contrast pairs of products that fall into specific product clusters. The last task produces information that can be used to create detailed product descriptions, which, for example, can be used by the Bureau of Labor Statistics to develop product checklists, an essential tool in developing price indices. PACT has been successfully tested in two product areas, PC software and telecommunications. PACT's implementation time needs to be shortened for its value to be fully realized.