When searching for empirical articles, you can search by terms, or keywords, related to your hypothesis. For example, if you were interested in the impact of gratitude on happiness, you may start with this basic search for happiness AND gratitude, each in a separate search box:
Perhaps there is a scholar working in your area of interest. You can search by author using the "AU Author" drop-down option (with the format: "last name, first name or first initial").
You can also limit your search by Methodology in the advanced search. Look for the Methodology box in the bottom, right corner under "Limit your results."