Television research suggests that three major television networks are following a policy of standardization and that a high degree of consonance in prime-time network programing results from constraints within the networks' organizational, economic, and ideological frameworks. A study further explored these results by examining a list of all regularly scheduled fall network prime-time programs from 1953 to 1984. From 2,891 programs coded into nine categories four hypotheses were generated: (1) the ranks of proportions of prime-time programing content among the networks would be similar; (2) there would be a negative trend in the number of programs offered on the networks' fall prime-time network; (3) there would be a negative trend in the number of program categories; and (4) there would be a positive trend in the average length of regularly scheduled programs. The findings indicated that action/adventure shows and situation comedies have dominated programing, with little diversity in the networks. In 1953 and 1954 there were 147 programs but by 1973, only 63. Program categories varied from a high of 25 in 1955 to 9 in 1979 and 1984; in 1953 and 1954 the average length of programs was 30 minutes, but by 1980 average length was one hour. Results show that the networks have been remarkably similar in content, and that this consonance reduces the ways people can screen themselves from media impact and demonstrates the networks' vested interest in maintaining the status quo. (SRT)