It is quite simple to limit to empirical studies in APA PsycInfo.
Once you have searched for your topic, choose the Additional Limits icon in the light blue box, below the search box. Scroll down to the Methodology section and choose Empirical Study.
APA Video: Peer-Reviewed Empirical Articles
What to Look For:
When reviewing a journal article, look for the following key components which identifies it as an empirical study:
Abstract: a comprehensive summary of the research
Introduction: a presentation of the research problem and related research
Method: a description of the data collection methods
Results: a summary of the findings / outcomes of the research
Discussion: an evaluation and interpretation of the research results
References: a listing of books, articles, etc. cited in the research.
Definition of Empirical
The APA Dictionary of Psychology defines empirical as: "derived from or denoting experimentation or systematic observations as the basis for conclusion or determination, as opposed to speculative, theoretical, or exclusively reason-based approaches" (pg. 327).
An empirical study, therefore, is one "based on facts, systematic observation, or experiment, rather than theory or general philosophical principle" (source).