When searching for empirical studies:
1. Some databases, such as PsycINFO, usually in the advanced search options, will have ways to limit your search by METHODOLOGY. In PsycINFO, for example, you can limit the METHODOLOGY to EMPIRICAL STUDY.
2. In other databases, use keywords such as:
....along with your subject terms.
phobias AND (subjects OR results OR methodology OR empirical)
3. For other types of methodologies, use the appropriate limit (for example, "clinical" or "qualitative") or these types of terms as keywords in your search strategy.
4. As always, please ask the Reference librarians for assistance!