An Arbitron or Nielsen measure of a market of television viewers. An ADI includes all jurisdictions within a metro area, which can receive the signal of a particular station. The United States has over 200 ADIs.
A market area designated by American Research Bureau (ARB) and used in Arbitron ratings surveys. ADI is analogous to A.C. Nielsen's Designated Market Area DMA and is similar to the Bureau of the Budget's Standard Metropolitan Statistical Area SMSA. Each ADI is an exclusive geographical area consisting of all counties in which the Home Market Stations receive a preponderance of viewing hours. Every county in the U.S. is assigned to one and only one ADI.