WORTH NOTING ON TV

* FRIDAY

On the Issues (PBS, 9-10 p.m.): Just in case public TV needed still another round of talking heads chewing on trendy public-affairs issues, this four-parter - airing on consecutive Fridays - has rushed in to fill the non-vacuum. Yet despite the boredom alarm set off by the approach of these programs, it turns out that their talkers are informed, reasonably articulate, and closer to the working heart of the matter under discussion than those on many such panels. The format, familiar from certain previous debate shows, takes about 15 panelists per show through hypothetical problems drawn from actual events in their field. They are questioned by the moderator - "cross-examined" might be the word at times - about how they'd respond to this development or that. This semi-Socratic method, a kind of watered-down law-school drilling, depends on the moderator's skills (and humor) for much of its success, and in this series the moderators are well-chosen. The opening program, for instance, "Washington Under the Infl uence," is moderated by ABC News correspondent Jeff Greenfield, who guides his impressive group through an imaginary but not-so-far-fetched scenario about the "Chemalot Corporation" and its efforts to buy favor in Washington. The host of the series, also well-chosen, is John Chancellor. * SATURDAY

MonsterVision (TNT, 8 p.m.-6 a.m.!): This series normally airs a marathon of campy horror-sci-fi flicks the last Saturday of each month. For June, it's giving us a 10-hour dose every Saturday, and to make it a little more palatable, it has brought in the popular - and very different - comedy team of Penn & Teller as hosts. Each evening is keyed to a theme - the first: "Very Special Special Effects," with Penn & Teller as "security guards" of the building - a format that lets them ply their comic tricks o n the strange objects within (Teller fences with a life-size chicken at one point). TNT is calling the whole thing "A Simple Television Experiment Gone Completely Berserk," and it probably has.

Please check local listings, especially for the PBS program.