In peer reviewed journals, there are basically three types of articles:

Research articles

Review articles

Commentaries

Research articles describe, in detail, an actual study conducted by the authors of the article. The research article includes a brief background on the subject matter justifying the need for the study, states the purpose of the study, describes the methods and results of the study, and provides a discussion of the results with any limitations of the study and conclusions the authors have drawn from the results. By reading a research article carefully, you can evaluate the strengths and weaknesses of the study and draw your own informed conclusions. Reading a research article carefully is very important.

Click here for steps in reading a research article

A review article is an objective summary of many research articles on a particular subject . The author(s) do not describe individual studies in detail, and may or may not have conducted studies in the area themselves. A review article provides a good summary of studies conducted on a topic, but you rely on the author’s evaluation of the actual studies. Since it is impossible to read every research article that comes out in every journal, review articles are a good way to "keep up with the latest". But if you want to be an expert on a particular topic, you need to go to the orignal source – the research articles themselves.

Commentaries are essays published in journals describing the author’s opinion on a topic.
The referencing is less extensive than in review articles, and the information presented is not as objective as in the review artlice. It can be fun to read the commentaries and letters to the editor in professional journals to listen to professionals get personal about their opinions!

Evaluating a Research Article