What type of data is typically collected over an extended period from a large group?

Consumer panels are a type of data collection that involves gathering information from a large, specific group of individuals over an extended period. This method allows researchers to observe changes in consumer behavior and preferences over time, which is invaluable for understanding trends and making informed marketing decisions.

By utilizing consumer panels, marketers can identify patterns in purchasing habits, reactions to new products, or shifts in attitudes towards brands, all of which can significantly influence marketing strategies. This ongoing data collection helps create a more dynamic picture of the market, as opposed to capturing static measurements at a single point in time.

The other types of data mentioned do not fit the description as precisely. Qualitative data, while insightful, typically focuses on non-numerical information and individual experiences rather than broad, prolonged group data. Secondary data refers to data that has been collected for another purpose and may not be designed for current, long-term analysis. Cross-sectional data represents a snapshot at one point in time rather than tracking changes over an extended period. Therefore, consumer panels are the most suitable option for collecting data from a large group over an extended period.