A total of 1,130 questionnaires were returned, for a response rate of 62 percent. Of these, 625 principals indicated their schools had an ISS program, while 505 did not. An examination of ISS program description data revealed eight possible components: ISS room, staffing/supervision, materials, academic work, reasons for assigning students to ISS, operational procedures, recordkeeping and evaluation, and counseling procedures. Some type of ISS program was in effect in 97 percent of high schools, whereas only 58 percent of junior high schools had such a program. In two-thirds of all schools, teachers were included in the ISS program. In 78 percent of the schools, some type of inservice training was provided for ISS personnel. Junior high school teachers placed more emphasis on using extra assignments during the ISS period, while other schools emphasized required assignments more. Restricted behavior during the ISS period included bathroom privileges, moving about the room, and socializing. Most ISS programs did not provide counseling, and 12 percent used parent conferences in conjunction with the ISS program. Junior high schools appeared to have the lowest success rate with ISS programs, while middle and other schools had the highest success rate. Eleven ISS programs in New York are described in detail. The survey questionnaire is appended. 227 references and 22 tables