Research articles: reports of original research studies.
Case studies: qualitative analyses of individual clients, programs, or institutions conducted to illustrate a problem, report on a potential solution to a clinical problem, or highlight a treatment or research need.
Review articles: critical analyses of previously published research articles on a topic.
Theoretical articles: reports that review existing research literature for the purpose of promoting a theory or philosophical approach.
Methodological articles: reports of new methodological strategies, proposed changes to current methodological strategies, and reviews of various data analyses problems, solutions, and issues. They may examine a genuine research study but do so for the purpose of illustrating a concept.
Brief reports: Depending on the journal, these may include short literature reviews on narrow topics, announcements of research discoveries, and comments about others’ research. Depending on the journal, they may or may not be peer-reviewed.