The Can-Dial Cancer Public Information System was the first program to use the telephone to provide the public with information on cancer. This volume describes the Can-Dial program and presents the results of a comprehensive, in-depth evaluation of this innovative cancer control technique. Included are findings on the utilization of the program, the differences between users and nonusers, and the effect which contact with the system has had on individuals' knowledge and behavior. The work will be extremely helpful to all those interested in ways of promoting cnacer prevention behavior, of evaluating types of health care services, and of understanding how people utilize resources.