Empirical: Based on data gathered by original experiments or observations.
Theoretical: Analyzes and makes connections between empirical studies to define or advance a theoretical position.
The most direct route is to search PsycInfo, linked above.
This will take you to the Advanced Search, where you can type in your key words at the top. Then scroll down through all the limiting options to the Methodology menu. Select Empirical Study.
In other databases without the Methodology limiter, such as Education Source, try keywords like empirical, study, and research.
Check for these components:
Look for visual cues of data collection and analysis: