WORTH NOTING ON TV

* THURSDAY

The Real World (MTV, 10-10:30 p.m.): A postmodern mix of TV formats if there ever was one - soap and "reality" show - is the idea behind the series starting its second season. A Los Angeles group of seven - aged 18-to-25 - move into a loft as a camera records their lives - their actions, feelings, and relationships. The seven are actors but the production is given a documentary feel, with cast members speaking directly to the camera to discuss their feelings. * FRIDAY

Investigative Reports (A&E, 9-10 p.m.): A look inside a prison is nothing new on documentaries, but "L.A. Behind Bars" examines one of the largest systems in the world: Los Angeles County Central, a huge, grim, dehumanizing place that puts merciless stress both on the inmates (6,000 of them) and on the guards (only 165). Host Bill Kurtis takes viewers on a detailed tour that covers everything from the preparation and serving of 18,000 meals a day to the segregation of certain inmates - like members of th e Bloods and Crips street gangs, who officials say account for most of the violence inside the walls. * SATURDAY

Front Page (Fox, 9-10 p.m.): Does this sound familiar? A weekly magazine show with five correspondents who cover topical news features - three major pieces each week - and focus on what are billed as provocative and relevant issues. That checklist could fit several network news magazines, but this one is Fox's entry in the familiar genre. Couple of twists, though: One of the correspondents is Ron Reagan, and the show's tone promises to be a little more contemporary in its feel. Shorter stories will also be included, along with commentary and reflections. The opening show includes segments on a Hollywood financial "scandal" and one on the sometimes troubling popularity of plastic surgery for teenagers.

Please check local listings for all programs.