Empirical Research (Primary Source): Studies that are based on observations or experiments. Clinical trials, case studies, and meta-analyses are typical empirical research.
Literature Review (Secondary Source): Articles that summarize the research on a particular topic. They often include a summary, a systematic review, and meta-analyses.
Case Study (Primary Source): Articles that provide real cases from clinical practice. They often include descriptions of symptoms, diagnosis, and treatment.
Clinical Trial (Primary Source): Studies that are often based on large cohorts of people. They typically include descriptions of methodology and control groups.
Position Paper (Secondary Source): Papers of opinions that reflect personal thoughts, or institutional beliefs, or a conclusion based on facts. Their typical goal is to persuade or influence the reader.
Book Review (Secondary Source): Papers of opinions that critique recent publications in the field. They tend to be brief and to the point.