ERIC (Education Resource Information Center) is an online database that contains
You can use three versions of ERIC. All provide access to the same data, but their interfaces are different. ERIC (EBSCO) and ERIC (ProQuest) are by subscription. ERIC (U.S. Department of Education) links to the freely available version of ERIC.
ERIC does not have a simple method to locate empirical research. Using "empirical" as a keyword will find some studies, but miss others. One technique is to search for "Research Reports". Use the Advanced Search. Type keywords into search boxes. Under More Search Options, see Document Type and choose Reports: Research
An alternative is to use terminology recommended by the ERIC thesaurus. Some useful keywords are: