1. Saddler, Delores MSN, RN, CGRN, Department Editor

Article Content

A Comparison of Quantitative and Qualitative Research Terms

The March/April edition of the SGNA News includes an article highlighting a qualitative research study conducted to obtain information on the latest technology and practices of gastrointestinal (GI) and endoscopy professionals (Wallace, 2007). This research study took place at the May 2006 meeting in San Antonio, TX, and included data from eight focus groups and 49 one-on-one informal interviews with vendors and attendees. The eight focus groups had an average of 6 participants engaged in a 1-hour group discussion. Each person in the one-on-one group participated in a 5-minute interview conducted in the exhibit hall. Participants included administrators, nurse managers, staff nurses, technicians, or SGNA nonmembers. All research participants were asked a series of questions related to current practices, equipment use, key industry challenges, and predicted future technology trends.


A qualitative research method is typical of the kind used in the report indicated above. This research method involves obtaining information and looking for common themes or ideas. Recurring themes from the SGNA study (Wallace, 2007), indicating current issues in GI practice were as follows: (a) keeping up with technology and competencies, (b) increasing offerings of advanced educational courses, (c) raising the level of respect for GI/endoscopy nursing in the field, (d) resolving the role of the associated and unlicensed assistive personnel, and (e) delineating GI professional roles. On the basis of the information gathered, solutions to resolve these challenges will be identified by the research team for implementation by SGNA.


Some people consider qualitative research as less valuable than the traditional quantitative method; however, the method used is totally up to the researcher and the purpose of the study. Both qualitative and quantitative research methods contribute to the body of knowledge.


Qualitative research is focused simply on "qualifying" information by exploring a topic from the perspective of knowledgeable informants. This approach makes a simple statement about the topic of investigation and treats participants as holistic beings. Quantitative research, conversely, quantifies data by using numbers and statistics. This approach identifies "how much," "differences between variables," and "how variables are associated." It uses objective measures and is very specific. The quantitative method may answer only one dimension of an issue and is often very focused on one aspect of knowledge.


In qualitative research, data are not numerical, yet they are very full and rich. A qualitative research study is described as a work in progress. Qualitative investigation is generally conducted in a natural setting in which the informant usually lives or works (e.g., work, prison, the endoscopy unit). Data collection usually occurs face-to-face and therefore does not provide the level of privacy that a quantitative study provides.


When conducting qualitative research, the researcher will often keep a personal journal, a field notes journal, and a methodological notebook. The personal journal includes the researcher's feelings and perspectives regarding the activity. The field notes describes observations related to the informants participating in the study, and the methodological notebook records anything related to the method (e.g., if the questions are not working, or if a new tape recorder is needed). This is especially important because study questions asked of informants are changed in qualitative research if it appears that the original study questions are not resulting in the type of data the researcher is after.


Quantitative research is logical and usually deductive, whereas qualitative research is consumer inductive. Once the data are obtained, the decision must be made as to how to use this data to make recommendations. If one were to compare the basic focus underlying quantitative and qualitative methods, qualitative methodology investigates themes and categories of data, whereas quantitative methodology emphasizes reliability and validity of the collected data.


Glesne (2006) summarized these major differences in qualitative and quantitative research as follows:


* Assumptions: In quantitative research, variables are identified prior to initiation of the study, and their relationships can be measured. Qualitative research has variables that are complex, interwoven, and are difficult to measure. Qualitative variables emerge from the study data and are not necessarily preidentified.


* Purposes: Quantitative research is predictive, general, and has causal explanations. Qualitative research is contextual, interpretative, and promotes basic understanding.


* Approach: Quantitative research begins with hypotheses and theory, uses formal instruments, reduces data to numerical indices, looks for the norm, and uses abstract language in the explanation. Qualitative research is natural, inductive, searches for patterns, uses description in the research report, and considers the researcher to be the data collection instrument.


* Role: The quantitative researcher is detached and objective. The qualitative researcher is emphatic, understanding, and has personal involvement.



The purpose of research is to fill gaps in knowledge. The nature of knowing is referred to as ontology versus epistemology. Ontology is concerned about whether the world exists and in what form it exists. In ontological quantitative research, a fixed reality exists that can be measured and apprehended to some degree of accuracy. In qualitative research from an ontological perspective, reality is complex and ever changing. Epistemology describes how you know what you know. In quantitative methods, the research process is done through objective observation and measurement. The qualitative epistemology researcher, however, believes that you come to know realities through interactions and explorations (Glesne, 2006).


In both methodologies, there are certain types of research designs. Designs for qualitative research include phenomenological, grounded theory, ethnographic, historical, philosophical, and critical social. Phenomenological research is both a philosophy and a research method. Its purpose is to describe experiences as they are lived, that is, to capture the lived experience of study participants (Burns & Grove, 2005). Grounded theory is an inductive research technique developed for health-related topics. The researcher uses this design to begin to build a theory around a topic of interest. Grounded theory has its roots in the data from which it is derived (Burns, 2001). Ethnographic research provides a means for studying cultures (Burns, 2001). Historical research examines events of the past (Burns, 2001). Philosophical research looks at and describes people's language, dress, food, traditions, and customs (Burns, 2001). And, finally, the critical social design gives some control over what is studied, how it is studied, and who gets the information. It is "designed to empower participants to take control of their life situations" (Burns, 2001, p. 62).


Designs in quantitative research are experimental, quasi-experimental, comparative, correlational, and descriptive. Experimental and quasi-experimental studies help to determine cause-and-effect relationships. Comparative studies establish cause-and-effect relationships in populations that can not be manipulated by the researcher (they are "naturally" occurring groups). Correlational studies establish that a relationship exists between two variables and provides the foundation for later experimental or quasi-experimental studies.


Quantitative research is the approach many of us shy away from because we feel very inadequate when reading this type of formal, technical research report. In quantitative research, data are converted to statistics or numbers. Most of the statistical analysis takes place through the use of some specialized computer software program; however, the data that are analyzed must be clear and accurate in order to get the appropriate results. Interpretation of the data is the responsibility of the researcher and not the statistician.


In a quantitative research study "tools" are used to gather data. These are valid and reliable measures, usually questionnaires, used to collect the study data. Terms such as reliability (whether a tool measure what it says it measures) and validity (whether the tool is appropriate, useful, and meaningful) are critical in quantitative work. According to Pedhauzer and Schmelkin (1991), a measurement tool cannot be valid if it is not reliable, but being reliable does not necessarily make it valid for the purpose the tool's author or user has in mind. In addition, Pedhauzer and Schmelkin stated that high reliability coefficients can be alluring to the extent that there is a danger of erroneously treating them as evidence of validity when they may not be valid in another study population or setting. Reliability and validity must always be confirmed in each study.


When reviewing a research report, the sample size should be considered before adopting the results. A result obtained with a random sample selection does not necessarily represent the entire population, and thus one should be very careful before adopting results without considering the sample and the sample size. For example, in a quantitative research study, a sample of 49 endoscopy nurses from Texas, among a membership of 8,000 national members, would not adequately represent the endoscopy nurses, so any conclusions that are based on the sample size of 49 should be carefully scrutinized. In any research study, the author should always list what method of research was used and should describe the sample. A true random sample should give everyone in the population an equal opportunity to be represented.


Sample size in a qualitative research study is generally 30 individuals or less. The aforementioned study (Wallace, 2007) consisted of eight focus groups and 49 single participants, which makes a large sample size for a qualitative study. The concern with large qualitative samples is that the data can be overwhelming when analyzed, and key aspects of the data might then be overlooked.


A descriptive analysis of the sample is always good information to be included when collecting study data. In the SGNA study, it may be important to know how many of each type of participant (vendor vs. member) was included, years of experience in endoscopy, role or job description, type or make up of unit, and any other organizations represented (SGNA is listed as the main organization).


When reading a research report, one must look for how the data were collected as well as how they were tabulated. As stated above, qualitative questions are designed to gather the information of interest to the researcher and can be modified as needed. Many qualitative interviews are tape recorded and later transcribed. There is no mention in the SGNA report as to how the information was documented and tabulated, information that would have been useful to know.


Other information to look for in a research report is how the researcher defines the key variables. Often, words do not convey the same meaning to all readers, and important terms and concepts should be defined for the reader. In the SGNA report, terms that could be defined for the reader to better know the population are seasoned, structured educational programs, and staffing obstacles. These terms initially bring to mind definitions for the reader that may not be consistent with what the researcher intended. Definitions should be defined both empirically (dictionary) and conceptually (what it means to the researcher). Many concepts are difficult to define and mean different things to different people (e.g., pain, hope, suffering, and disparity).


Understanding the differences between qualitative and quantitative research methods is useful in evaluating the credibility of a reported study. Understanding that there is no "right" methodology, rather different methodologies for different purposes can help you as a research consumer read and evaluate research reports more knowledgeably and confidently.




Burns, N., & Grove, S. (2005). The practice of nursing research: Conduct, critique, and utilization (5th ed.). St. Louis, MO: Elsevier. [Context Link]


Glesne, C. (2006). Becoming qualitative researchers: An introduction (3rd ed.). Boston: Pearson. [Context Link]


Pedhauzer, E., & Schmelkin, L. (1991). Measurement, design, analysis: An integrative approach. Hillsdale, NJ: Erlbaum. [Context Link]


Wallace, J. K. (2007). Research finds a need for expanded education. SGNA News, 25(2), 5. [Context Link]