Qualitative or quantitative research?
Quantitative research
Quantitative approaches are used to study measurable phenomena. This type of research seeks to explain phenomena by collecting data and analysing it using mathematical methods. The aim is to generalise findings. Since it is usually impossible to study an entire population, sampling is used by studying a representative group of that population.
The value of quantitative research also lies in its ability to test hypotheses through statistical analysis.
Methods
Quantitative studies can be either experimental or observational. Here are a few examples below (this list is not exhaustive).
Experimental studies:
- Randomized controlled trial
Observational studies:
- Cohort (prospective longitudinal)
- Case-control study
- Cross-sectional study
- Ecological study (population-based)
Qualitative research
Qualitative research aims to describe, analyse and understand representations, behaviours and interactions that cannot be captured through quantitative approaches. It focuses on discourse, observed actions or behaviours. It is commonly used in sociology, anthropology and psychology. However, it is also highly relevant to clinical research, particularly for understanding the lived experiences of patients and healthcare professionals.
Qualitative research allows exploration, description, understanding and explanation. It is the approach of choice for in-depth analysis of complex, non-quantifiable phenomena within their “natural” environment.
Methods
The qualitative approach may use a variety of methods, such as:
- Interviews (individual or group, and conducted in open, semi-structured or structured formats)
- Observation
- Document/material analysis (text corpora, images, etc.)
It requires rigour in both data collection and analysis.
Differences
Below are some examples of key differences between quantitative and qualitative research:
| Quantitative research | Qualitative research |
|---|---|
| Verify hypotheses | Generates hypotheses |
| Examines a set of people: sampling allows representative coverage of people in the population | Examines a set of ideas: sampling must allow representative coverage of ideas or concepts |
| Explains the "how" and evaluates the "how much" | Explains the "why" and "what it means" |
| Obtains numerical estimates of frequencies and significance from large numbers of participants | Collects fleshed-out, contextual and detailed information from a small number of participants |
Mixed methods research
Quantitative and qualitative approaches are not mutually exclusive; on the contrary, they can be combined. This is referred to as mixed methods research.
Several reasons justify combining these approaches:
- The need for qualitative analysis to interpret quantitative results
- The need for quantitative approaches to generalise qualitative findings
- The need to explore (qualitative analysis) and measure (quantitative analysis)
Useful links
Bibliographical references
To get started: the L'enquête et ses méthodes collection from Armand Colin
To go further: Les recherches qualitatives en santé, edited by Joëlle Kivits, Frédéric Balard, Cécile Fournier, Myriam Winance, published by Armand Colin.
L'analyse qualitative en sciences humaines et sociales, by Pierre Paillé and Alex Mucchielli, published by Armand Colin.
Research Methods in Palliative, Supportive and End-of-Life Care (second edition), by Irene J. Higginson, Eduardo Bruera, Massimo Costantini, David Currow, Philip J. Larkin and Nancy Preston, Oxford University Press.
For inspiration from thinking abroad: Ethics of Research Involving Humans. Tri-Council Policy Statement (Social Sciences and Humanities Research Council of Canada, Natural Sciences and Engineering Research Council of Canada, Canadian Institutes of Health Research)
Research training
Consult the section dedicated to research on the CNGE website
Consult the online course