Quantitative Research

Original Editor - Angeliki Chorti Top Contributors - Angeliki Chorti

Introduction[edit | edit source]

Quantitative research is a type of research that assumes that the phenomena under study can be measured and involves methods that:

  • gather data using measurement (numerical data)
  • analyse data by using quantitative statistical analysis techniques.


Quantitative Research Methodology[edit | edit source]

Methodology refers to the overall approach taken in a piece of research. [2] In quantitative research, it encompasses the general principles of investigation that guide how such a study is designed and conducted in order to answer a quantitative research question.

The methodological steps for quantitative investigations are found below.

Step 1: The Research Question[edit | edit source]

The core of any research is the research question(s). [2] Research question(s) guide the design and methods used in a study, being key to not only identifying gaps in knowledge but also refining and adjusting existing knowledge. [2]

In quantitative research, the nature of the research question may be descriptive / normative or explanatory.

Descriptive / normative research questions[edit | edit source]

Descriptive research questions provide a descriptive account of a phenomenon within an established framework of knowledge; this approach is often used when aiming to develop a fuller account of an observation and is sometimes combined with identifying some relationships of potential interest. [2] For example, a researcher may choose to utilise survey methods to investigate the characteristics, perceptions and behavious about a particular condition in a specific population. [3]

Normative research questions are similar in their purpose to descriptive research questions, but also include an additional objective of comparing data gathered with a criterion or standard. [4]

Explanatory research questions[edit | edit source]

Explanatory research questions usually test a hypothesis i.e. a prediction that the study sets out to either retain or reject, by means of statistical inference testing. [5]

Step 2: Research strategy[edit | edit source]

Quantitative investigations may be primary or secondary, depending on the source of research knowledge.

Primary research[edit | edit source]

Primary investigations involve the actual research study i.e. information gathered through self-conducted research methods. The decision on primary research is influenced by the number / quality of available information. A search for available evidence is common before any research study. Primary research study is usually based on gaps in available knowledge.

Secondary research[edit | edit source]

Secondary research accesses primary data through previously conducted quantitative research studies. Systematic reviews and meta-analyses that gather and analyse clinical/experimental primary studies rank higher than single quantitative studies in the hierarchy of evidence. [6]

Designs[edit | edit source]

There are two main types of primary quantitative research designs: [1]

  • Survey
  • Experimental

Survey research designs[edit | edit source]

Survey designs are most frequently employed in healthcare epidemiology research.[7] Surveys may be used to gain insights into opinions and practices in large samples; they can be descriptive and/or be used to test associations. [7]

Experimental research designs[edit | edit source]

In experimental research designs, the researcher can manipulate one (or more) variable(s), the independent variable, and study the effect on a dependent variable. [1] There are many types of experimental designs; one of the most important is the randomised controlled trial.

Randomised controlled trials[edit | edit source]

Randomised controlled trials are considered top methods in the hierarchy of evidence when testing the link between cause and effect in clinical interventions. [8][9]

Key differences between different forms of quantitative research[edit | edit source]

Key differences between different forms of quantitative research are found below. Distinctions have been simplified for clarity and some overlap may exist between characteristics. [2]

Descriptive / Normative Explanatory
Type of research Primary Primary
Nature of research question Fairly specific and largely definite Highly specific and definite; Declarative
Research design Structured, sequential and largely predetermined Highly structured, sequential and predetermined
Data collected Quantitative Quantitative
Relationship to theory Aims to develop or elaborate theory Hypothesis testing

References[edit | edit source]

  1. 1.0 1.1 1.2 Watson R. Quantitative research. Nurs Stand. 2015 Apr 1;29(31):44-8.
  2. 2.0 2.1 2.2 2.3 2.4 Sim J., Wright C. Research in Health Care: concepts, designs and methods. Nelson Thornes: Cheltenham, UK. 2002
  3. Mouchtouri V., Agathagelidou E., Kofonikolas K., Rousou X., Dadouli K., Pinaka O., et al. Nationwide Survey in Greece about Knowledge, Risk Perceptions, and Preventive Behaviors for COVID-19 during the General Lockdown in April 2020. Int J Environ Res Public Health. 2020 Nov 28;17(23):8854.
  4. Hedrick T., Bickman L., Rog D. Applied Research Design: A Practical Guide. Sage Publications, Newbury Park. 1993
  5. Hazra A., Gogtay N. Biostatistics Series Module 2: Overview of Hypothesis Testing. Indian J Dermatol. 2016 Mar-Apr;61(2):137-45.
  6. Kapoor M. Types of studies and research design. Indian J Anaesth. 2016 Sep; 60(9): 626–630.
  7. 7.0 7.1 Safdar N., Abbo L., Knobloch M., Seo S.Research Methods in Healthcare Epidemiology: Survey and Qualitative Research. Infect Control Hosp Epidemiol. 2016 Nov; 37(11): 1272–1277.
  8. Evans D. Hierarchy of evidence: a framework for ranking evidence evaluating healthcare interventions. J Clin Nurs. 2003 Jan;12(1):77-84.
  9. Wallace S., Barak G., Truong G., Parker M. Hierarchy of Evidence Within the Medical Literature. Hosp Pediatr. 2022 Aug 1;12(8):745-750.