There are two kinds of research: Quantitative and Qualitative
Quantitative is research that generates numerical data. If it helps, think of the root of the word "Quantitative." The word "Quantity" is at its core, and quantity just means "amount" or "how many." Heart rates, blood cell counts, how many people fainted at the jazz festival-- these are all examples of quantitative measures.
Qualitative, on the other hand, is a more subjective measurement. Think of the root of the word again, this time it's "Quality." If someone is called a quality person or someone's selling a high quality product, they're being measured in subjective terms, rather than concrete, objective terms (like numbers.) Qualitative research includes things like interviews or focus groups.
Just like when we examine whether or not our article is an example of Primary Research, the best way to examine what kind of data your article uses is by reading the article's Abstract, Methodologies, and Results sections. That will tell you how the research was conducted and what kind of data (qualitative or quantitative) was collected.
An example of what to look for in the Abstract can be seen here:
You can see that data was evaluated (66% of students were in compliance with school immunization requirements), a strategy was implemented (letters and emails were sent to student's parents/guardians), and at the end of the study, new quantitative data is reported (99.6% of students were in compliance with vaccination requirements).
Finding qualitative research can be trickier, since it can often take more time to collect. Examples of qualitative data include things like interview transcripts, focus group feedback, and journal entries detailing people's experiences and feelings. The easiest way to search for a qualitative study is to include the word "qualitative" as a keyword in your database search along with the search terms about the topic you're interested in.
Check out the video below to see an example of searching for qualitative research in CINAHL.