RMResearch Metrics AfricaResearch. Evidence. Better Decisions.
HomeResearch hubStudy designLiterature reviewResearch methodsBiostatisticsField researchScientific communicationContact us
Portfolio ↙
Home/Research hub/Study design

RESEARCH GUIDE / 01

Build a study that can answer the question.

Study design is the structure connecting a research question to credible evidence. A strong design makes the population, measurements, comparisons, timing, ethics, and analysis clear before data collection begins.

A researcher mapping a question into a complete study design
Core questionWhat design can answer this question with the least avoidable bias?
Best forProposals and protocols
What you should leave withA defensible study blueprint

Follow the reasoning

How the pieces fit

Start in order, but do not treat research as a straight line. Later evidence often sends you back to fix an earlier decision—and that is part of doing the work properly.

01

Define the problem

Describe the real-world issue, who it affects, what is already observed, and why the unanswered part matters.

Quality check: Keep the problem specific enough to investigate—not a whole field of study.
02

Write the research question

Name the population, main exposure or intervention, comparison where relevant, outcome, place, and time period.

Quality check: A focused question makes the literature search, variables, and analysis easier to align.
03

Set objectives and hypotheses

Use one overall objective and specific objectives that each lead to a measurable result. Add hypotheses when the study will test relationships or differences.

Quality check: Avoid objectives that introduce concepts not present in the main question.
04

Choose the design

Select a cross-sectional, case-control, cohort, experimental, qualitative, mixed-methods, or other design based on the question—not convenience alone.

Quality check: Descriptive questions, causal questions, and lived-experience questions require different designs.
05

Plan the population and sampling

Define eligibility, sampling frame, sampling method, sample size reasoning, recruitment, and how non-response will be handled.

Quality check: The people you can reach are not automatically the population you want to understand.
06

Pre-plan measurement and analysis

Define every key variable, choose valid measurement tools, identify likely confounders, and map each objective to an analysis before collecting data.

Quality check: Include ethics, data protection, bias control, limitations, and a realistic timeline.

See it in context

Worked example: phone use and sleep

Research questionAmong university students in Kenya, is late-night smartphone use associated with poorer sleep quality during the academic semester?

An analytical cross-sectional survey could estimate the prevalence of late-night use and test its association with a measured sleep-quality score at one point in time.

Population

Registered university students meeting stated eligibility criteria

Exposure

Frequency or duration of smartphone use after a defined night-time hour

Outcome

Sleep quality measured with a stated, appropriate instrument

Other variables

Age, course workload, caffeine use, living arrangement, and other justified factors

Analysis

Descriptive summaries followed by an appropriate adjusted regression model

Limitation

A cross-sectional design cannot establish which behaviour came first

Before you move on

Questions your work should answer

✓

The question names a population and a measurable outcome.

01
✓

The design matches the type of question being asked.

02
✓

Eligibility, sampling, and sample-size reasoning are explicit.

03
✓

Every objective maps to variables and a planned analysis.

04
✓

Bias, confounding, ethics, privacy, and limitations are addressed.

05
A sophisticated analysis cannot rescue a design that collected the wrong evidence.

Follow the next decision

Keep the research story connected.

A good question should shape the literature search; the evidence should sharpen the design; and the methods should make the result possible to understand and challenge.