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Research Guides@Tufts

Industries & Market Research

Resources and tips on locating information on specific industries and markets.

Classification Systems Basics

Much of the information on U.S. industries and businesses is organized by two major industry classification systems: the North American Industry Classification System (NAICS) and the Standard Industry Classification System (SIC).  Both are hierarchical, numerical classification systems.  Internationally-focused sources often apply other industry classification systems.

Companies engaged in a wide range of activities may have multiple industry classifications, although usually one industry is considered primary.

The classification systems themselves do not provide direct links to industry information but many online databases and print directories enable searching by these codes. The systems also provide useful descriptions of industries and sub-industries as well as inspiration for search terms.

Major Classification Systems