"Quantitative research is a systematic process used to gather and statistically analyze information that has been measured by an instrument. Instruments are used to convert information into numbers. It studies only quantifiable concepts (concepts that can be measured and turned into numbers)." It examines phenomenon through the numerical representation of observations and statistical analysis.
Langford, R. ( 2000). Navigating the Maze of Nursing Research. Elsevier.
Example of Quantitative Research
Hinkle JL.Variables explaining functional recovery following motor stroke. J Neurosci Nurs, 2006 Feb;38(1):6-12
Abstract: Few well-designed descriptive studies focus exclusively on patients after motor stroke. This study describes a cohort of participants after motor stroke and assesses the extent to which five key variables explain the variation in functional recovery 3 months after stroke. Prospective data were collected (N=100) on age, lesion volume, motor strength, cognition, and poststroke function during the acute care hospital admission. Instruments included magnetic resonance imaging (MRI) to provide a measure of lesion volume, the Mini-Mental State Examination (MMSE) and the Neurobehavioral Cognitive Status Examination (NCSE) to measure cognitive status, and the National Institutes of Health Stroke Scale (NIHSS) to measure motor strength. The Functional Independence Measure (FIM) was used to measure baseline function and functional recovery 3 months after stroke. Descriptive and hierarchical multiple regression analyses were used to describe the cohort and predict functional recovery. The means for key variables during acute care were 65 (+/-15) years of age, lesion volume 21.5 (+/-44.7) cm3, NIHSS 6.34 (+/-3.55), MMSE 24.38 (+/-4.82), NCSE 64.33 (+/-13), and FIMTM 94.05 (+/-19.31). Age, cognitive status, and initial function accounted for 42% of the variance in functional recovery 3 months after stroke. Results indicate that neuroscience nurses need to add cognition to their focus during the fast-paced acute phase of care following motor stroke.
"Qualitative research implies a focus on qualities of a process or entity and meanings that are not examined or measured in terms of quantity, amount, frequency, or intensity. Qualitative research can mean the analysis of open-ended questions that respondents are asked to write on a survey. It also can refer to what is thought of as naturalistic research, a general label for qualitative research methods that involve the researcher going to a natural setting, that is, to where the phenomenon being studied is taking place."
Qualitative research includes many methods:
Cohen, M.Z. (2006). Introduction to Qualitative Research. In LoBiondo-Wood, G., Haber, J. (Eds), Nursing research. Methods and critical appraisal for evidence-based practice (pp 131-132). St. Louis: Mosby Elsevier.
Example of Qualitative Research
Harrison, T., Angel, J., Mann, A. (2008). Mexican American women aging with childhood-onset paralytic polio. Qualitative Health Research, 18(6),767-74.
Abstract: In this study the life histories of 11 Latinas of Mexican American descent aging with permanent impairment related to childhood-onset paralytic polio were explored. These women, age 45 to 62 years, were interviewed 3 times each. Field notes, audiotaped interviews, life course charts, and demographic data were used to collect data chronicling childhood to present day. In the results we present a thematic representation of the societal and cultural influences on the life course trajectories of these women.
"Broadly speaking, quantitative research is thought to be objective whereas qualitative research often involves a subjective element. It is thought that in gaining, analysing and interpreting quantitative data, the researcher can remain detached and objective. Often this is not possible with qualitative research where the researcher may actually be involved in the situation of the research."
Consider a study being undertaken into waiting times in the Accident & Emergency (A&E) Department of a hospital.
A quantitative study, measuring how long people wait, can be purely objective. However if the researcher was wanting to discover how patients felt about their waiting time, they would have to come into contact with the patients and make judgements about the way they answered their questions. If the researcher asked the patient "how are you feeling having waited an hour to be seen by the doctor?" they would almost certainly register the patients non-verbal behaviour as well as document the response; in this way the researcher is adding a subjective element to the study.
Quantitative research is inclined to be deductive. In other words it tests theory.
This is in contrast to most qualitative research which tends to be inductive. In other words it generates theory.
Using the A&E waiting time example again, the quantitative approach might test the hypothesis that " Patients attending this A&E department do not wait for more than one hour to be seen by a doctor". A qualitative approach which explores the feelings of patients who wait an excessive time to be seen by the doctor might generate the theory that "patients who experience an excessive wait to be seen by the doctor experience an enlargement of the symptoms that brought them to the department".
Quantitative designs of research tend to produce results that can be generalised. Using our A&E example, we should find that, at least for the department under consideration, the results of the quantitative study tend to hold true. Providing, of course, that the research was conducted in an appropriate manner using appropriate sampling techniques.
However, qualitative studies tend to produce results that are less easy to generalise. This has to do with the problem of the sample used at the time. We all know, for example, that our feelings about waiting can change dependent on our particular set of circumstances. Even if the researcher encountered the same group of clients on another day, they may find different results. Generally, it is difficult to generalise with qualitative results.
Lastly here, the most obvious difference between quantitative research and qualitative research is that quantitative research uses data that are structured in the form of numbers or that can be immediately transported into numbers.
If the data can not be structured in the form of numbers, they are considered qualitative. (Note that qualitative data can sometimes be handled in such a way as to produce quantitative data. e.g. the researcher exploring feelings of patients can analyse the responses in clusters that are negative or positive so as to produce a figure/percentage of negative patient and positive patient feelings).
When a researcher selects their approach to a study it should be a reflection of which approach is most suitable for the topic under consideration. However it is also reasonable to suggest that it also reflects the bias of the researcher. The majority of medical research is quantitative (and considered to produce "hard", generalisable results) while much of nursing research is qualitative (and considered to produce "soft" results).
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