Which data collection method primarily uses secondary sources of information?

The observation method is primarily focused on collecting data through directly observing subjects or events in their natural environment without manipulation or intervention. While it can involve gathering insights from secondary sources, such as existing studies or reports to frame the observation context, its fundamental approach relies on direct observation rather than existing data.

The other options, while valid data collection methods, tend to be more focused on primary data gathering. Focus groups involve collecting qualitative data from group discussions, experiments manipulate variables under controlled conditions to observe outcomes, and surveys collect responses directly from participants regarding their opinions or behaviors. Each of these methods typically generates new, firsthand data rather than relying on previously gathered information. Thus, the observation method stands out in the context of relying on whether it can use secondary sources, whereas the other methods create new insights through active data collection.