MONDAY A Teacher's Story (Discovery cable, 9-10 p.m.): First of a three-parter about people who have taken big steps forward in a field where that's hard to do - education. The opener - ``Socrates for Six-Year-Olds'' - covers the career of Matthew Lipman, who had the wonderful idea of establishing the Institute for the Advancement for Children at New Jersey's Montclair State College. Honeymooners Anniversary Special (CBS, 10-11 p.m.): TV's classic comedy series gets a loving backward look from Audrey Meadows - the woman who played Alice Kramden - as she and Art Carney (Ed Norton) share inside stories about the show and its star, the late Jackie Gleason. The legendary Kramden apartment has been recreated - complete with beat-up icebox - and episodes two and three of the series will be repeated for the first time. Korea: The Unknown War (PBS, 9-11 p.m.): Bunched together over three days - ``Civil War''-style - this series uses eye-witnesses, documentary clips, and lots of helpful historical background to examine the terrible conflict that Americans found themselves in before many knew where the country was. It looks at the war from both a strategist's and foot soldier's perspective. (Continues Tuesday and Wednesday). TUESDAY NOVA (PBS, 8-9 p.m.) They're called ``smart weapons'' - robotic devices that seek out, follow, and destroy ships, planes, tanks, and other targets. ``Killing Machines'' looks at the geopolitical impact of what some call the ``great equalizers,'' since small nations can often get their hands on them. Please check local listings for all programs, especially on PBS.