Research methods are the techniques used to structure inquiry and analyze information, and fall into several categories: quantitative research, qualitative research, or mixed methods research.
Quantitative research is the investigation of phenomena that can be quantified. Numbers and statistics resulting from a formal measurement will be a major component of quantitative research. Research articles that are quantitative will generally include multiple tables and/or charts. The title of the article may give you clues about the research method, as will an examination of the “Methodology” section of the article. Quantitative research involves a rigorous and controlled design. For example, quantitative research on patient stress would rely primarily on measurable outcomes, possibly utilizing measurable indicators such as patient blood pressure and pulse rate of the sample group.
Qualitative research is the investigation of phenomena through the collection of rich narrative material. For example, a study on patient stress may rely upon in-depth interviews or focus groups involving the sample group regarding their feelings of stress or anxiety, possibly before and after an intervention. As with quantitative research, the article title and abstract may also provide clues as to the research type. Qualitative studies may have no tables with quantitative information beyond a description of the sample group, such as by age or sex.
Mixed methods research includes quantitative data as well as qualitative data, which is collected and analyzed to address different but related outcomes. The article title or abstract may provide clues as to whether the research is mixed methods research.
Here are three ways to limit to quantitative studies in CINAHL:
1) One simple strategy is to limit the Publication Type to a particular type of primary research article that in most cases uses a quantitative design: the Clinical Trial.
Start by typing clinical trial in the search box. Then change the field on the right to PT Publication type. This searches for the term Clinical Trial in the Publication Type field
You can select multiple publication types in addition to Clinical Trial such as Randomized Controlled Trial and Research Instrument in the Advanced Search under Limit Your Results -> Publication Types by pressing the CTRL key as you select (as you can see below, I also selected Research which is broader):
Remember that every article record isn’t necessarily tagged in this manner, so you may have to consult a librarian to develop a more comprehensive strategy.
2) Another approach to finding quantitative research articles is to use subject terms related to quantitative designs, such as Experimental Studies or Quasi-Experimental Studies.
To search for specific types of experimental studies, try checking the suggest Subject Terms box before you search for the term.
Then click on the term "Experimental Studies" in the results list to see the hierarchical tree view. This will display broader and subordinate term. Click the 'Explode' box to include all of the subordinate subject headings in your search:
3) CINAHL also provides subject terms for a variety of statistical tests under the heading (MH "Data Analysis, Statistical+"). Click explode to cover subordinate terms:
Remember that the presence of statistical tests may provide a clue that the study employs a quantitative design. Consider checking the Research Article box in conjunction with this method. You could use this approach in tandem with the methods I listed above to find quantitative studies. Keep in mind this strategy is unique to CINAHL and not every quantitative article is tagged using these headings; however, it may help pick up a fair amount of relevant studies.