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Cleveland Clinic Florida Goldblatt Medical Library: Qualitative vs. Quantitative Research

Qualitative vs Quantitative

  Qualitative Quantitative
Keywords Complexity, contextual, inductive logic, discovery, exploration  Experiment, random assignment, independent/dependent variable, causal/correlational, validity, deductive logic
Purpose Understand a phenomenon Discover causal relationships or describe a phenomenon
Sample Purpose sample, small Random sample, large
Data Focus groups, interviews, field observation Tests, surveys, questionnaires
Methods/ Design Phenomenological, grounded theory, ethnographic, case study, historical/narrative research, participatory, research, clinical research Experimental, quasi-experimental, descriptive, methodical, exploratory, comparative, correlational, developmental (cross-sectional, longitudinal/prospective/cohort, retrospective/ex post facto/case control)

From Eastern Kentucky University Library:


Qualitative research is defined as "research that derives data from observation, interviews, or verbal interactions and focuses on the meanings and interpretations of the participants." (Holloway and Wheeler, 1995)

Qualitative research can be challenging to find as these methodologies are not always well-indexed in bibliographic databases. This help guide will provide some tips and information to guide you in your search for qualitative research articles through databases, such as PubMed and CINAHL.

For Any Database

Strategy 1: Use Subject Headings 

Databases use controlled keywords (known as thesaurus or subject terms) to categorize each record stored. PubMed, for example, uses Medical Subject Headings (MeSH), a highly structured index of terminology. The subject headings vary for each database according to their indexing system.  The term "qualitative research" is indexed in PubMed as "Qualitative Research" or "Nursing Methodology Research", while in CINAHL the subject heading "Qualitative Studies" is complemented by more detailed terms, including "Phenomenological Research" and "Grounded Theory".

Strategy 2: Use Text Words

This strategy uses text or keywords that might specifically identify qualitative research and searches the titles, abstracts and keywords of records held in the databases. Some Text Words include: qualitative, ethnograph*, phenomenol*, ethnonurs*, grounded theor*, purposive sample, hermeneutic*, heuristic*, semiotics, lived experience*, narrative*, life experiences, cluster sample, action research, observational method, content analysis, thematic analysis, constant comparative method, field stud*, theoretical sample, discourse analysis, focus group*, ethnological research, ethnomethodolog*, interview*.

Strategy 3: Use Qualitative Research Filters

Qualitative Research Filters are pre-formulated search strategies that have been constructed by librarians to help you retrieve articles in databases that deal with qualitative research. You can use the filter and then combine the results with your subject.

Tips from University of Washington Health Sciences Library:

See below for database search strategies. 

The following are tips that can help you find quantitative research articles. These tips work best when your initial search produces a large amount of results. 

Tip: Although CINAHL does not have a checkbox to limit your search to either quantitative or qualitative research, it is sometimes helpful to add vocabulary that describes quantitative research tools, methodology or assessments. In the advanced search screen page, you can add a search box that will include words that describe quantitative research.

For example, your quantitative research search statement may read:

quantitative OR t-test OR “Chi Square” OR covariance OR anova OR instrument* OR mean OR median OR "standard deviation" OR coefficient*

 Tip: CINAHL allows you to filter by publication type.  If your initial search has returned lots of results, you might try using the Publication Type limiter to select only Clinical Trial and/or Randomized Controlled Trial.  These are types of quantitative studies. 

Purdue University West Library: 


Database Strategies


  • Explode the Qualitative Studies subject heading, and see what you get. Explode will include the following CINAHL Headings: Action Research, Ethnographic Research, Ethnological Research, Ethnonursing Research, Grounded Theory, Naturalistic Inquiry, Phenomenological Research.
  • Experiment with related CINAHL subject headings such as Focus Groups, Narratives, Interviews (explode Interviews to include Semi-Structured Interview, Structured Interview, Unstructured Interview), Descriptive Research, Descriptive Statistics, Audiorecording, Videorecording, Diaries, Observational Methods (explode to include Non-Participant Observation, Participant Observation, Structured Categories, Unstructured Categories), Projective Techniques (explodes to include Pictorial Methods, Verbal Projective Techniques), Vignettes, etc.
  • Refine/Limit the set to Clinical Queries. Select within the drop-down Clinical Queries menu: Qualitative-High Sensitivity; Qualitative-High Specificity; Qualitative-Best Balance. High Sensitivity is the broadest search, to include ALL relevant material, but may also include less relevant materials. High Specificity is the most targeted search to include only the most relevant result set, but may miss some relevant materials. Best Balance retrieves the best balance between Sensitivity and Specificity.
  • Refine/Limit the set to Publication Types that are qualitative by definition, for example Anecdote, Interview, Metasynthesis, etc.
  • Use Text Words to find articles missed by CINAHL headings (see General Strategies #2)
  • Use a Qualitative Research Filter for CINAHL. 

Combine these results with your search subject. The search below will automatically be executed for you (the search may be modified once you are in CINAHL):

(MH “action research”) or (MH "Audiorecording") or (MH "cluster sample+") or (MH "constant comparative method") or (MH "content analysis") or (MH "discourse analysis") or (MH "ethnographic research") or (MH "ethnological research") or (MH "ethnography") or (MH "ethnonursing research") or (MH "field studies") or (MH "focus groups") or (MH "grounded theory") or (MH "Historical Records") or (MH "Interviews+") or (MH "Narratives") or (MH “naturalistic inquiry”) or (MH "observational methods+") or (MH "phenomenological research") or (MH "phenomenology") or (MH "purposive sample") or (MH "qualitative studies") or (MH "qualitative validity+") or (MH "questionnaires") or (MH "thematic analysis") or (MH "theoretical sample") or (MH "Videorecording+") or TX colaizzi* or TX constant comparative or TX constant comparison or TX cooperative inquir* or TX co-operative inquir* or TX co operative inquir* or TX Corbin* TX data saturat* or TX discourse* analysis or  TX emic or TX etic or TX ethnon* or TX field research or TX field stud* or TX focus group* or TX Foucault* or TX giorgi* or TX Glaser* or TX grounded analysis or TX grounded research or TX grounded studies or TX grounded study or TX grounded theor* or TX heidegger* or TX hermeneutic* or TX heuristic or TX human science or TX husserl* or TX life experiences or TX life stor* or TX lived experience* or TX merleau ponty* or TX narrative analysis or TX qualitative or TX participant observ* or TX phenomenol* or TX purpos* sampl* or TX questionnaire* or TX semiotics or TX spiegelberg* or TX Strauss* TX van kaam* or TX van manen*

Mixed Methods Research Design

CINAHL has the following Subject Headings that may be of use: Multimethod Studies or Triangulation

You can also search your topic with the following suggested text words:

  • mixed model* or mixed design* or multiple method* or multimethod* or triangulat*

Tips from University of Washington Health Sciences Library:


  • Use appropriate Medical Subject Heading (MeSH) terms in your search, such as:
    • Qualitative Research [research that derives data from observation, interviews, or verbal interactions and focuses on the meanings and interpretations of the participants. Year introduced 2003]
    • Interviews as Topic [conversations with an individual or individuals held in order to obtain information about their background and other personal biographical data, their attitudes and opinions, etc. It includes school admission or job interviews. Year introduced: 2008 (1980)]
    • Focus Groups [a method of data collection and a qualitative research tool in which a small group of individuals are brought together and allowed to interact in a discussion of their opinions about topics, issues, or questions. Year introduced: 1993]
    • Grounded Theory [The generation of theories from analysis of empirical data. Year introduced 2015]
    • Nursing Methodology Research [research carried out by nurses concerning techniques and methods to implement projects and to document information, including methods of interviewing patients, collecting data, and forming inferences. The concept includes exploration of methodological issues such as human subjectivity and human experience. Year introduced: 1991(1989)]
    • Anecdotes as Topic [brief accounts or narratives of an incident or event. Year introduced: 2008(1963)]
    • Narration [the act, process, or an instance of narrating, i.e., telling a story. In the context of MEDICINE or ETHICS, narration includes relating the particular and the personal in the life story of an individual. Year introduced: 2003]
    • Video Recording [the storing or preserving of video signals for television to be played back later via a transmitter or receiver. Recordings may be made on magnetic tape or discs (VIDEODISC RECORDING). Year introduced: 1984]
    • Tape Recording [recording of information on magnetic or punched paper tape. Year introduced: 1967(1964)]
    • Personal Narratives as Topic [works about accounts of individual experience in relation to a particular field or of participation in related activities. Year introduced: 2013]
    • Observational Study as Topic [A clinical study in which participants may receive diagnostic, therapeutic, or other types of interventions, but the investigator does not assign participants to specific interventions (as in an interventional study). Year introduced: 2014]

NOTE: Inconsistent indexing in PubMed. For example, grounded theory articles are not always indexed for qualitative research. Need to TextWord search for additional terms: “grounded theory”, “action research”, ethnograph* etc.

Additional MeSH terms that may be applicable to your topic include: Attitude of Health PersonnelAttitude to DeathAttitude to Health; or Health Knowledge, Attitudes, Practice.

  • Limit your search to specific Publication Types, such as:
    • Interview [work consisting of a conversation with an individual regarding his or her background and other personal and professional details, opinions on specific subjects posed by the interviewer, etc. Year introduced: 2008(1993)]
    • Diaries [works consisting of records, usually private, of writers' experiences, observations, feelings, attitudes, etc. They may also be works marked in calendar order in which to note appointments and the like. (From Random House Unabridged Dictionary, 2d ed) Year introduced: 2008(1997)]
    • Anecdotes [works consisting of brief accounts or narratives of incidents or events. Year introduced: 2008(1999)]
    • Personal Narratives [works consisting of accounts of individual experience in relation to a particular field or of participation in related activities. Year introduced: 2013]
    • Observational Study [A clinical study in which participants may receive diagnostic, therapeutic, or other types of interventions, but the investigator does not assign participants to specific interventions (as in an interventional study).Year introduced: 2014]
  • Use Text Words to find articles missed by MeSH terms (see Strategy 2)
  • Use a Quality Research Filter:
    • 1.  PubMed Health Services Research (HSR) Queries
      • Select Topic - Specific Queries from the PubMed home page and then Health Services Research Queries.
      • This page provides a filter for specialized PubMed searches on healthcare quality and costs.
      • Enter your search topic and select Qualitative Research under Category
    • 2.  Qualitative Research search filter example [copy and paste the following modified filter into PubMed and combine your subject terms with this search filter]

(((“semi-structured”[TIAB] OR semistructured[TIAB] OR unstructured[TIAB] OR informal[TIAB] OR “in-depth”[TIAB] OR indepth[TIAB] OR “face-to-face”[TIAB] OR structured[TIAB] OR guide[TIAB] OR guides[TIAB]) AND (interview*[TIAB] OR discussion*[TIAB] OR questionnaire*[TIAB])) OR (“focus group”[TIAB] OR “focus groups”[TIAB] OR qualitative[TIAB] OR ethnograph*[TIAB] OR fieldwork[TIAB] OR “field work”[TIAB] OR “key informant”[TIAB])) OR “interviews as topic”[Mesh] OR “focus groups”[Mesh] OR narration[Mesh] OR qualitative research[Mesh] OR "personal narratives as topic"[Mesh] OR (theme[TIAB] OR thematic[TIAB]) OR "ethnological research"[TIAB] OR phenomenol*[TIAB] OR "grounded theory"[TIAB] OR "grounded study"[TIAB] OR "grounded studies"[TIAB] OR "grounded research"[TIAB] OR "grounded analysis"[TIAB] OR "grounded analyses"[TIAB] OR "life story"[TIAB] OR "life stories"[TIAB] OR emic[TIAB] OR etic[TIAB] OR hermeneutics[TIAB] OR heuristic*[TIAB] OR semiotic[TIAB] OR "data saturation"[TIAB] OR "participant observation"[TIAB] OR "action research"[TIAB] OR "cooperative inquiry"[TIAB] OR "co-operative inquiry"[TIAB] OR "field study"[TIAB] OR "field studies"[TIAB] OR "field research"[TIAB] OR "theoretical sample"[TIAB] OR "theoretical samples"[TIAB] OR "theoretical sampling"[TIAB] OR "purposive sampling"[TIAB] OR  "purposive sample"[TIAB] OR "purposive samples"[TIAB]  OR "lived experience"[TIAB] OR "lived experiences"[TIAB] OR "purposive sampling"[TIAB]  OR "content analysis"[TIAB] OR discourse[TIAB] OR "narrative analysis"[TIAB] OR heidegger*[TIAB] OR colaizzi[TIAB] OR spiegelberg[TIAB] OR "van manen*"[TIAB] OR "van kaam"[TIAB] OR "merleau ponty"[TIAB] OR husserl*[TIAB] OR Foucault[TIAB] or Corbin[TIAB] OR Strauss[TIAB] OR Glaser[TIAB] 

Mixed Methods Research Design

PubMed does not have suitable MeSH terms for mixed methods research. Search your topic with the following suggested text words using the quotes and truncation symbol*:

  • “mixed model*” OR “mixed design*” OR “multiple method*” OR multimethod* OR triangulat*

Tips from University of Washington Health Sciences Library: