How many research questions should a thesis have?

Many theses have one main question, sometimes with two or three sub-questions that break it down. More than that often makes a thesis hard to finish. Your department's guidelines and your supervisor decide what is expected.

What is the difference between a research question and a hypothesis?

A research question asks what you want to find out. A hypothesis is a testable prediction about the answer, used mainly in quantitative studies. Qualitative research often works with questions only.

Can I change my research question later?

Yes, refining the question during the project is normal, especially after the literature review or a pilot study. Larger changes should be agreed with your supervisor and may need to be reflected in a registered topic or ethics approval.

Should a research question be answerable with yes or no?

Usually not. Yes or no questions tend to produce thin answers. Questions starting with how, to what extent or why invite analysis, although a closed question can work as a sub-question or hypothesis.

Research question: how to write one, with examples

A research question states precisely what your study sets out to find out. A good one is clear enough that a reader knows what kind of answer to expect, narrow enough to be answered in your project, researchable with data and methods you can access, and connected to an existing debate. Almost every later decision, from method to chapter structure, follows from it.

From topic to question in five steps

Start with a topic you find interesting and that fits your programme, for example “remote teaching”.
Narrow it by population, context, time or aspect: “remote teaching in first-year engineering courses since 2020”.
Find the gap. Read recent literature and ask what is unknown or contested. Our guide to finding a research gap shows where to look.
Decide what kind of answer you need: a description, a comparison, an explanation or an evaluation.
Phrase the question with precise terms, then test and revise it.

Types of research questions

Type	Asks	Example	Typical methods
Descriptive	What is the case?	How do first-year engineering students use recorded lectures?	Survey, document analysis, observation
Comparative	How do groups or settings differ?	How does engagement differ between in-person and remote lab sessions?	Survey, quasi-experiment, case comparison
Relational	Is there a relationship?	Is the use of recorded lectures associated with exam results?	Correlational analysis
Explanatory	Why or how does something happen?	How do students explain their participation in remote labs?	Interviews, process tracing, experiment
Evaluative	How well does something work?	To what extent did a new online tutoring scheme improve completion rates?	Evaluation design, mixed methods

Choose the type before the method. The guide to research methodology explains how the two fit together.

Weak and strong questions compared

Weaker version	Problem	Stronger version
What about social media and students?	No focus, no clear concept	How do undergraduate students in Germany use Instagram to find study information?
Is remote teaching good?	Value-laden, yes or no	To what extent did remote lab sessions change self-reported engagement among first-year engineering students in 2024/25?
How can climate change be solved?	Far too broad for one study	Which barriers do small municipalities in Austria report when applying for climate adaptation funding?

Frameworks that help

FINER is a widely used checklist: is the question Feasible, Interesting, Novel, Ethical and Relevant? It originated in clinical research, but works for most fields.

PICO (Population, Intervention, Comparison, Outcome) structures questions about effects, mainly in health sciences. Variants such as PICo or SPIDER exist for qualitative work.

You do not have to use a framework, but writing out each element often reveals what is still vague.

Checklist for your draft

Every key term is precise or can be defined in the thesis.
The population, context and time frame are clear.
You know what data you need and how to get it.
The question can be answered within your time and word limit.
The answer is not obvious before you start.
It connects to at least one ongoing debate in the literature.
It is free of built-in assumptions about the result.

Note: in many programmes the topic and question must be registered with the examination office or approved in a proposal. Check when your question becomes binding and how much it can still change.

Main question and sub-questions

A common pattern is one main question supported by two to four sub-questions. Each sub-question should contribute a building block to the main answer, often matching a chapter:

Main question: To what extent did remote lab sessions change engagement among first-year engineering students?
Sub-question 1: How is engagement defined and measured in engineering education?
Sub-question 2: How did students rate their engagement in remote and in-person sessions?
Sub-question 3: Which factors do students name to explain differences?

A quick test

Explain your question in one sentence to someone from a different subject. If they understand what you want to find out and why it matters, you are on the right track. If you need three sentences of background first, the question is probably still too broad or too vague.

Next steps

Once your question holds up, use it to plan a focused literature search and to write the rationale and methods of your research proposal. Discuss the question with your supervisor before you collect any data. More guides on getting from topic to question are in the literature section.

How to formulate a research question