Empirical articles are based on an experiment or study. The authors will report the purpose of the study, the research methodology, and results. This is a familiar structure for empirical articles (IMRAD):
In describing the purpose of their study, authors will present a mini literature review to discuss how previous research has led up to their original research project.
Also called:
Example: The prevalence of sleep disorders in college students: Impact on academic performance
In PsycINFO, use the Methodology limiter to narrow to empirical study (original research).
You may also want to try clinical case study, clinical trial, or treatment outcome depending on your topic.
Both empirical articles & literature reviews are:
They are different in one important way:
Empirical articles report the findings of a research study, while review articles assess the findings of a variety of studies on a topic.
Review articles summarize or synthesize content from earlier published research and are useful for surveying the literature on a specific research area. Review articles can lead you to empirical articles.
There are several types.
In PsycINFO, use the Methodology limiter to narrow to literature review.
You may also want to try systematic review or meta analysis.
A research letter is a shorter version of a full original research article. Be aware that this is not the same as a letter to an editor in an academic journal.
Letters are often written in response to articles, editorials, and other materials. They do not go through a peer-review process, but can give you insight into the scholarly conversation around a topic. They are not included in all databases, but you may find them included in some of them.
Research Notes are short articles. They may be called short reports, technical notes, case reports etc. Be aware that some limiters in databases may also include correspondence in a Notes limiter.