Clearly reviews the properties of important contemporary measures of association and correlation. Liebetrau devotes full chapters to measures for nominal, ordinal, and continuous (interval) data, paying special attention to the sampling distributions needed to determine levels of significance and confidence intervals. Valuable discussions also focus on the relationships between various measures, the sampling properties of their estimators and the comparative advantages and disadvantages of different approaches.
This third annual report presents comparative year-to-year data on the nature of violence on television across programme genres and channel types in the United States. It contains an analysis of how the new television rating system was initially implemented and tracks trends over three years in the use of programme advisories and content codes. It also evaluates public service announcements designed to prevent handgun violence among adolescents. Finally, it provides new analyses of `high risk' presentations of violence most likely to adversely affect younger audiences.