Companies are ranked according to their percentage increase in sales during the last five years (1977-81). To be included in the INC. 100, each company must meet these criteria:

1. The company is an independent, publicly held corporation in a manufacturing, mining, or service industry. Utilities, banks, insurance companies, and other financial institutions are excluded.

2. The company was publicly held as of December 31, 1981.

3. The company shows an operating/sales history of at least five years, with an increase in its fiscal 1981 closing figure. Firms showing growth in the 1977-81 base period but a sales decline in the last year are excluded.

4. The company's 1977 sales were at least $100,000 but less than $25 million.

Sales and income figures are gathered from 10-Ks, prospectuses, annual reports, and various data bases and directories. Additional information is collected from stock reports, trade magazines, and general business publications. By applying the four criteria above, as well as a five-year growth rate of at least 500, INC. pared the number of companies that potentially qualified for listing from 11,000 to less than 200.

Telephone interviews were conducted with corporate executives to verify the figures, and an editorial team led by senior editor Bradford W. Ketchum, Jr., and assistant editor Carol Torres then selected the 1982 INC. 100.