What research method uses selected households to measure media viewing habits?

The correct answer is media panels, as this research method specifically involves the use of a selected group of households to systematically measure and analyze media consumption patterns over time. Media panels rely on longitudinal data, allowing researchers to track changes in viewing habits and preferences, which can provide a comprehensive understanding of audience behavior.

Media panels generally employ technology, such as set-top boxes or online tracking tools, to collect data on what participants are watching, when they are watching, and how often. This approach helps media companies and advertisers assess the effectiveness of their content and marketing strategies based on real-time consumer behavior.

In contrast, focus groups involve discussions with a small group of individuals and do not provide quantitative data on viewing habits. Surveys can collect data from a broader audience but may not track media habits as thoroughly as media panels. Case studies focus on in-depth analysis of specific instances or cases rather than providing generalizable data about media consumption across selected households.