Three films by writer/director John Singleton are collected in this three-pack: BOYZ N THE HOOD, POETIC JUSTICE AND HIGHER LEARNING. BOYZ N THE HOOD (1991, Rated R): John Singleton emerged from USC film school with his passionate script already written, and at age 23 he made the film that spawned a score of ghetto dramas. From the opening shot--a sign reading Stop --to the final message of Increase the Peace, Singleton`s desire to galvanize his audience is clear. The violence destroying South Central Los Angeles is seen through the eyes of Tre Styles (Cuba Gooding Jr.), whose intelligence and common sense would be wasted in the `hood if not for his father, Furious (Laurence Fishburne), who imparts discipline and responsibility to his son. Tre`s friends aren`t so lucky, though, especially Doughboy (Ice Cube), who has been in and out of institutions since childhood and now sits on his porch with a forty in his hand and a pistol in his waistband. Singleton is ambitious enough to tackle a host of problems, from African American business practices to the bias of the SAT test, but the real power of the film lies in the performances of its principals. Cuba Gooding, in his first role, doesn`t let Tre come off like a goody two-shoes, while Ice Cube gives a tragic nobility to a young man who knows he`s doomed. POETIC JUSTICE (1993, Rated R): Pop princess Janet Jackson plays Justice, a hairdresser and poet living in South Central Los Angeles, in the second film from director John Singleton. Justice saw her first love killed over a gang grudge, and ever since she`s been aloof and lonely. She agrees to go on a road trip with her friend, and meets Lucky (Tupac Shakur), a love-struck mailman who soon finds that Justice will not be easily won over. As they discover that they have ideas about life in common, Justice feels that she is not as alone as she had thought. HIGHER LEARNING (1994, Rated R): For the incoming freshman at Columbus University, academic worries see