It is widely believed that television viewing has a negative impact on school achievement. This belief is supported by negative statistical associations sometimes found between school achievement and amount of television viewing; that is, heavy TV viewers tend to show poorer achievement than light viewers. One possible explanation of this association is that television viewing has a detrimental effect on cognitive development. This research review extensively examines this possibility. The research literature examined included work on: (1) the cognitive nature of children's television viewing, including viewing behavior, attention, comprehension, and arousal; (2) the effects of television viewing, including displaced activities, general knowledge, attentional processes, task perseverance and impulsivity, creativity and imagination, and reading; (3) modifiers of these effects, particularly coviewing by parents, and critical viewing skills programs; and (4) the relationship of these effects to schooling. The review concluded that analysis provided little support for most of the common beliefs about the negative influence of television on children. However, the conclusion that television had no major effects was difficult to support, since the review also reported that little research has been conducted on several major issues, including the influence of entertainment television on children's academically relevant knowledge. Also, reported was that some of the existing research could be challenged on methodological grounds. In addition, the review offers a research critique and suggestions for future research. (Sixteen pages of references are appended.) (MM)