1. Original research: These are detailed studies reporting original research and are classified as primary literature. They include hypothesis, background study, methods, results, interpretation of findings, and a discussion of possible implications.
2. Review article: Review articles provide a critical and constructive analysis of existing published literature in a field, through summary, analysis, and comparison, often identifying specific gaps or problems and providing recommendations for future research. These are considered as secondary literature since they generally do not present new data from the author's experimental work. Review articles can be of three types, broadly speaking: literature reviews, systematic reviews, and meta-analyses.
3. Clinical case study: Clinical case studies present the details of real patient cases from medical or clinical practice. The cases presented are usually those that contribute significantly to the existing knowledge on the field. The study is expected to discuss the signs, symptoms, diagnosis, and treatment of a disease. These are considered primary literature.
4. Clinical trial: Once again, specific to the field of medicine, clinical trials describe the methodology, implementation, and results of controlled studies, usually undertaken with large patient groups. Clinical trials also require practical work experience, as well as, high standards of ethics and reliability.
5. Methodologies or Methods: These articles present a new experimental method, test, or procedure. The method described may either be completely new, or may offer a better verison of an existing method. The article should describe a demonstrable advance on what is currently available.
6. Perspective, opinion, and commentary: Perspective pieces are scholarly reviews of fundamental concepts or prevalent ideas in a field. These are usually essays that present a personal point of view critiquing widespread notions pertaining to a field. A perspective piece can be a review of a single concept or a few related concepts. These are considered as secondary literature.
7. Book review: Book reviews are published in most academic journals. The aim of a book review is to provide insight and opinion on recently published scholarly books.
Majumder, Kakoli. (2015). 6 Article types that journals publish: A guide for early career researchers. Editage Insights. https://doi.org/10.34193/EI-A-6147
Types of journal articles. (2020). Springer Nature. Retrieved from: https://www.springer.com/gp/authors-editors/authorandreviewertutorials/writing-a-journal-manuscript/types-of-journal-articles/10285504
