While an empirical study is any research publication that shares an experiment or observation conducted by the author(s), the many disciplines that intersect in Child Study and Human Development have different types of research articles that are sometimes tricky to find.
Several of the recommended subject databases, specifically PsycARTICLES and PsycINFO, include filters that you can add to your search or results to only show specific types of publications (including systematic reviews).
Jumbo Search is a great place to start because it searches many of the Tisch Library's resources all at once. However, it doesn't search everything, and so using subject specific databases like the ones in the curated lists below can help you find more resources.
Some databases only provide citation information to an article or resource rather than the full text. Other times, you may find something on Google Scholar to which Tufts does not have instant access. Interlibrary loan can help provide you with access to the resources that you need with help from other libraries and universities.