This report summarizes the findings of a 2-year longitudinal study of a number of aspects of the effects of television on three small Canadian communities, one of which began receiving broadcasts for the first time during the study. The three communities were roughly matched for population (650-870 people), population of areas served by the towns, income, language spoken (English dominant), proportion of citizens born in Canada, occupational status in the population and major kinds of occupations available. At the beginning of the study, however, one community had no television reception (reception of a Canadian network began shortly after the first phase of the study was completed); the second received only one network (Canadian); and the third received four networks (one Canadian and three U.S.). The major variables investigated in relation to television viewing were (1) children's verbal and physical aggressive behavior, (2) children's reading skills, (3) children's cognitive development (verbal ability, spatial ability and verbal and figural ideational fluency), (4) children's sex role perceptions and (5) the extent of the participation of all age groups in community activities in terms of the available settings for such activities. These variables were investigated at the beginning of the study and 2 years later. Cross-sectional comparisons were made among the communities for given age ranges in addition to longitudinal comparisons within each community. (BH)