After three years on CBS' powerhouse Monday-night schedule--and two consecutive years in TV's "top ten" list--Family Affair moved to a Thursday berth for its fourth season on the air. Despite this displacement, not to mention fresh competition from NBC's long-running Daniel Boone and the ABC upstart The Ghost and Mrs Muir, the series retained its huge following, remaining securely fastened into the "Number Five" ratings position. Beyond the shift to a different evening, very little had changed on Family Affair proper. We still find bachelor engineer Bill Davis (Brian Keith) gamely coping with the pressures of surrogate parenthood as guardian of his orphaned nephew Jody (Johnnie Whitaker) and nieces Buffy (Anissa Jones) and Cissy (Anissa Jones). Likewise still on hand is Bill's supremely efficient British manservant Mr. French (Sebastian Cabot), who has grown to like his role as the children's "male nanny"--with reservations, of course. This season's guest stars include the magnificent Ida Lupino as a titled British lady whom Mr. French fondly remembers as his former sweetheart, a London barmaid named Maude; a very young Darlene Carr (remember her as Karl Malden's daughter on Streets of San Francisco?) as a starry-eyed teenager who develops a crush on the hapless Bill; former B-western star Bob Steele as. . .a former B-western star; and in an unusually serious episode, Dana Andrews as a troubled ex-convict who has trouble going straight. Also showing up with increasing frequency is Gregg Fedderson, the son of Family Affair creator Don Fedderson, who after a brief apprenticeship in character parts is seen in the recurring role of Cissy's boyfriend Gregg Bartlett. Perhaps the most memorable episode this season is "What's So Funny About a Broken Leg," hastily written to accommodate the fact that costar Anissa Jones' leg was really in a cast. Certainly the most elaborate installment is the two-part Season Four opener, wherein the entire family seriously considers bidding farewell to New York City and moving bag and baggage to Tahiti!