By Quick answer: Which UX research method should I use?
- Why / needs — interviews, field studies, diary studies.
- Does it work? — usability testing (moderated or unmoderated).
- How to organise? — card sorting, tree testing.
- How many / how much? — surveys, analytics, A/B tests.
- Mix — qualitative for why, quantitative for scale.
Key takeaways
- Start with the decision you need to make, then pick the method.
- Watching behaviour beats asking about it.
- Small, frequent research rounds beat one big study.
- Analytics show what happens; interviews and tests show why.
- Share findings fast — research nobody acts on is wasted.
Research methods aren't a menu to order from — they're tools for answering specific questions. Pick the wrong tool and you'll get confident answers to the wrong question: a survey that "proves" users want a feature they'll never use, or an A/B test that says what happened but never why. Nielsen Norman Group's widely used framework sorts methods by what they reveal1. Here's the practical version.
Start with the question
| Your question | Methods | Type |
|---|---|---|
| What do users need? What's their context? | Interviews, field studies, diary studies | Qualitative, attitudinal and behavioural |
| Can people use this design? | Usability testing (moderated or unmoderated) | Qualitative, behavioural |
| How should we organise content? | Card sorting, tree testing | Both |
| How many people do X? What do they think at scale? | Surveys, analytics | Quantitative |
| Which version performs better? | A/B tests | Quantitative, behavioural |
| How do people use the product over time? | Diary studies, longitudinal analytics | Both |
By product stage
Discovery
Interviews, field studies, diary studies, competitor analysis — understand the problem space.
Design
Usability tests on prototypes, card sorting, tree testing — check designs before building.
Launch and growth
Analytics, A/B tests, surveys, in-app feedback — measure and refine.
Method notes
User interviews
One-to-one conversations about real past experiences. Ask what people did, not what they would do — the principle behind The Mom Test3. See 50 user interview questions.
Usability testing
Give participants tasks and watch. Five users per round typically reveal most problems; iterate and test again2.
Surveys
Measure attitudes at scale once you know what to ask. Keep them short; avoid leading questions.
Analytics
Funnels, cohorts and paths show what people do — not why.
A/B tests
Compare versions with real traffic to establish cause; needs enough users and careful design4.
Card sorting and tree testing
Card sorting reveals how people group content; tree testing checks whether they can find things in your proposed structure.
Diary studies
Participants record experiences over days or weeks — great for habits and context.
A lightweight research rhythm
- Weekly: two or three user conversations.
- Every design cycle: a five-user usability test on the prototype.
- Monthly: review analytics and support themes.
- Quarterly: a survey or deeper study on a strategic question.
- Always: share findings within 48 hours in a short, visual summary.
Want an expert view of your product? A mobile app UX audit combines heuristic review with evidence from your users.
Key terms, defined
Qualitative research — explains why. Quantitative research — measures how many or how much. Usability test — observing people using a design. Card sorting — participants group content into categories. Tree testing — testing whether people can find items in a navigation structure. Diary study — participants record experiences over time.
Frequently asked questions
What are the main types of UX research?
Qualitative research (interviews, usability tests, field studies) explains why people behave as they do; quantitative research (surveys, analytics, A/B tests) measures how many or how much. Research can also be attitudinal (what people say) or behavioural (what they do).
How many users do I need for a usability test?
Nielsen Norman Group's research suggests five users per round find most usability problems in a design; run several small rounds rather than one large one. Quantitative studies need much larger samples.
What's the difference between user interviews and usability tests?
Interviews explore people's experiences, needs and context. Usability tests observe people trying to complete tasks with a design to find where it fails.
When should I use a survey?
When you need to measure attitudes or behaviours across many people, after you've used qualitative research to know what questions matter. Avoid using surveys to discover needs from scratch.
What is card sorting?
A method where participants group content items into categories that make sense to them, helping you design navigation and information architecture.
How do I do UX research on a small budget?
Interview five users via video calls, run quick usability tests with clickable prototypes, use free survey tools, and review analytics and support tickets. Small, regular studies are affordable and powerful.
Sources
- Nielsen Norman Group — When to use which user-experience research methods
- Nielsen Norman Group — Why you only need to test with 5 users
- Rob Fitzpatrick — The Mom Test
- Kohavi, Tang & Xu — Trustworthy Online Controlled Experiments
- Checked October 23, 2026. Figures that change — fees, salaries, prices — are reviewed every six months; if something is out of date, tell us.
Where to go from here
- 50 user interview questions — for the most-used method
- Mobile app UX audit — expert research on your app
- Career guidesHow to get a UX researcher job in 2027: choosing methods, interviews, usability tests, synthesis, mixed methods and research that changes decisionsHow to get a UX researcher job in 2027: choosing methods, interviews, usability testing, synthesis, mixed methods, AI in research, pay and a plan.
- Career guidesInformation architecture skills employers want in 2027: organising content, navigation, labels, taxonomies, card sorting and tree testingInformation architecture skills employers want in 2027: content inventories, navigation, labelling, taxonomies, card sorting, tree testing and search.
- Career guidesHow to get a conversion rate optimization job in 2027: research, hypotheses, experiments and the evidence hiring managers wantHow to get a CRO specialist job in 2027: research methods, hypotheses, A/B test design, analysis, the portfolio that proves it, pay and a plan.
- Startups in IndiaTop VC firms in India by stage and focus — and how to pick the right one to pitchTop VC firms in India grouped by stage — seed, early and multi-stage — with their focus areas and a practical method for choosing which investors to pitch.
- App developmentThe mobile app development process: 7 stages explained simplyThe 7 stages of mobile app development — discovery, design, planning, development, testing, launch and growth — what happens in each and how long.
- Templates & tools50 user interview questions that uncover real problems — grouped by goal, with the questions to avoid50 user interview questions for discovery and usability research, grouped by goal, with a simple script and the leading questions to avoid.
Get the ideas, not the noise.
Sign up with Google and we’ll send you short UX psychology tips by email — why people tap, stall and leave, and what to do about it. Unsubscribe anytime. Prefer something to keep? Get the free Laws of UX guide as a PDF.
See your product through your users' eyes.
A behavioral UX audit of your app or SaaS product: why users hesitate, stall and leave, and a prioritized fix list. Fixed price, 2–4 weeks.