Research design

Introduction to research design

There are three common approaches to conducting research. These are not specific data collection or analysis techniques, rather, they are the broader, overarching research approach.

The approach you take to your research must align with your aims and objectives. Your chosen approach will then inform your research methods; that is, how you go about collecting and analysing data.

  1. Quantitative research utilises numbers and statistics to describe characteristics of a group, test and measure differences between groups, or examine relationships between variables.
  2. Qualitative research focuses on words, concepts, perceptions, experiences, or ideas. It is used to gain a deeper understanding of the nature or complexity of a phenomenon and generally answers “why” and “how” questions.
  3. Mixed Methods research combines quantitative and qualitative methods to produce a more complete understanding of the research topic. The collection of qualitative and quantitative data can be done sequentially or simultaneously.






Measures, counts, scores​

Numbers, statistics

More objective​

Describes, interprets, explains​

Meaning, experiences, people​

More subjective​

Both qualitative and quantitative ​

Sequential or simultaneous​

Methodology (framework guiding research activities)​

Deductive approaches​

Can be used to test hypotheses or theories

Inductive approaches​

Can be used to develop descriptions, explanations, or theories from the data

Both inductive and deductive – combined

Methods (how we collect and analyse the data)​

Audits, close-ended survey questions, clinical outcomes, experiments

Random sampling​

Statistical and descriptive analyses

Interviews, focus groups, open-ended survey questions​

Purposive sampling​

Thematic analysis​

A combination of methods to produce and analyse qualitative and quantitative data 


Randomised Controlled Trials (RCTs)

  • A RCT involves randomly assigning participants to either an experimental group or a control group. The experimental group receives an intervention and the control group usually receives an alternative intervention (standard practice). ​The two group are then followed up to see if there are any differences between them in outcomes of interest.
  • A RCT could be used to test the effectiveness of a falls prevention programme for community-dwelling older adults at high risk of future falls.

Pre-post design

  • A pre-post study (also called before and after study) measures outcomes in a group of participants before and after an intervention is implemented.
  • A pre-post-study could be used to measure change in the quality-of-life outcomes for people attending a multidisciplinary pain service.

Cohort studies

  • Cohort studies are a type of longitudinal study where people are grouped based on a common characteristic and are followed over time to investigate the development of an outcome factor.
  • A cohort study could be used to explore health and wellbeing outcomes of colorectal cancer patients over a 2-year period.

Case control studies

  • A case control study compares people who have a disease or outcome of interest (cases) with people who don’t have the outcome of interest (controls).
  • A case control study could be used to investigate potential risk factors associated with chronic kidney disease.

Cross-sectional studies

  • Cross-sectional studies involve studying a group of people at a single point in time to determinewhat factors may be related to a particular outcome.
  • A cross-sectional design could be used to examine the differences between rural and non-rural residents’ health service utilisation.

Qualitative description

  • Qualitative description studies produce informed narrative descriptions of phenomena by exploring people’s experiences and perspectives.
  • A qualitative description study could be undertaken to explore health workers’ experiences during the initial phases of the COVID-19 pandemic.


  • Phenomenological studies examine and describe individuals’ lived experiences within the world.
  • A phenomenological study could be undertaken to deeply examine individuals’ experiences of studying to become a nurse while living with cancer.

Grounded theory

  • Grounded theory aims to produce or construct an explanatory theory which is ‘grounded’ in data that has been systematically collected and analysed.
  • A grounded theory approach could be taken to develop a theory of professional identity for emerging healthcare professions.


  • Ethnography involves observing and/or interacting with participants in their real-life environment.
  • An ethnography study could explore the nature of interprofessional communication and team work within a subacute care setting.

Case study research

  • Case studies are used to generate an in-depth, multifaceted understanding of a complex issues.
  • A case study could be undertaken across two organisations (or sites) that have implemented a collaborative care model, to explore the factors that influenced the outcomes of the newly implemented model.

Action research

  • Action research seeks to improve practice by developing solutions and implementing them as part of the research process.
  • Action research could be undertaken with clinicians, healthcare consumers, and carers to improve equity and access to community-based clinical services.


  • Both quantitative and qualitative data are collected and merged together to produce findings that are more than the sum of their individual parts
  • For example, researchers might conduct a convergent mixed methods study to explore the role of a health service embedded researcher. The researchers conducting the case study collect data related to the research outputs (e.g., ethics applications submitted, grant applications, conference presentations) attributable to the embedded researcher (quantitative data). They also conduct interviews with people that have worked with or been supported by the embedded researcher, to explore the mechanisms by which they have produced the research outputs and achievements (qualitative data). The quantitative and qualitative data are merged to produce insights above and beyond the quantitative and qualitative findings.

Explanatory sequential

  • Two phase design where quantitative data is collected and analysed first, then qualitative data is collected and analysed to explain or add depth to the quantitative data.
  • For example, for an evaluation study of an exercise program for older people, researchers first collect quality-of-life outcomes (quantitative data) from program participants. They then conduct interviews with a subset of program participants to explore the elements of the program that influenced their quality of life, and how (qualitative data). In this sense, the qualitative findings explain the quantitative outcomes.

Exploratory sequential

  • Two phase design where qualitative data is collected and analysed to inform a theory, instrument, intervention etc. The quantitative phase may be used to test the theory, instrument, intervention with the results further developing
  • For example, for a project that aims to define the role of health navigator workers, researchers conduct interviews with health navigators to explore their perspectives and experiences of their roles, and the activities or tasks they perform in their daily practice (qualitative data). The researchers could use that data to develop key performance indicators (KPIs) for health navigator workers which in turn could be used to measure the performance of health navigator workers in the same and/or other settings (quantitative data). In this way, the qualitative data is used to build a quantitative measurement tool (KPIs) which can then be used with a larger sample and potentially validated as a performance measure.

In deciding which approach is right for your research project you may want to consider:

The nature of your research aims and research questions

Each research approach has a different purpose and addresses a different type of question. Consider which category your research questions and aims fall under:

Nature of research aims


Recommended approach


Exploratory research investigates a problem which is not clearly defined. It is useful for research questions that have not previously been studied in-depth.

Qualitative approach


Confirmatory research (aka hypothesis testing) aims to measure or quantify something.

Quantitative approach

Both exploratory and confirmatory

Research that uses both of these approaches to address the same question.

Mixed methods approach

The methodological approaches used in previous studies

It can also be helpful to look at the approaches used by other researchers in the field. Pay particular attention to studies with similar research aims and objectives – what approach have they undertaken? What strengths and limitations did they describe by using this approach?

Practicalities and available resources

When designing a research project you will likely face the challenge of what is theoretically the best research design (i.e., the most scientifically rigorous) and what is practical or feasible given your resources.

Some considerations:

  • Access to data
  • Time
  • Cost
  • Equipment and software
  • Knowledge & skills

Tip: Mixed-methods research requires a sound understanding of both quantitative and qualitative approaches. This can be tricky for first time researchers, so it may be more feasible to use a mono method (i.e., either quantitative or qualitative) to begin with.