TV RATINGS : Familiar Shows Still Head Nielsen List

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Television viewing patterns followed familiar patterns last week, with NBC and its “The Cosby Show” again proving to be the favorites among the households monitored by the A.C. Nielsen Co. NBC had six of the 10 most-watched programs in its column and averaged a 16.1 rating for the week, compared to 13 for ABC and 12.6 for CBS. (Each rating point represents 904,000 households).

* ABC’s medical drama “HeartBeat” hasn’t won any hearts since rejoining the Thursday-night schedule two weeks ago. The show placed 72nd among the week’s 81 prime-time programs, attracting viewers in about 6.3 million homes, compared to about 26.9 million for the top-rated “Cosby Show.”

Show Points Share 1. “The Cosby Show” 29.8 45 (NBC) 2. “A Different World” 26.1 39 (NBC) 3. “Cheers” 25.4 38 (NBC) 4. “Roseanne” 23.4 34 (ABC) 5. “Who’s the Boss?” 22.5 34 (ABC) * “HeartBeat” 7 11 (ABC)