The TV viewing situation involves an active transaction between the child, the TV, and the TV viewing environment. The TV viewing transaction is a blend of passive and active cognitive activities. Children begin to watch TV systematically at around 2 1/2 years of age because at that time they have the cognitive ability to aappreciate the meaning of the dynamic flow of images and sounds it presents. Evidence exists that preschool children look at the parts of a television program that are understandable, and that they engage in alternate activities such as toy play when the program momentarily is not understood. Preschoolers also use their peers' behaviors as cues for directing their visual attention in the TV viewing environment. One passive aspect of TV viewing may be called"attentional inertia": the longer a TV viewer continuously maintains visual attention to the television, the more probable it is that he or she will continue to do so. Although in general the young child stops attending to incomprehensible program material, attentional inertia may occasionally lead the child to new cognitive discoveries. TV viewing in young children is not simply the mesmerizing passively receptive activity it is represented to be in popular books. Directions for further research are suggested. (Author/RH)