ImpactMojo
Browse Premium
Skip to content
Back to ImpactMojo
Interactive Lab

Survey Design Lab

Craft survey instruments — questions, scales, bias tests, and piloting. Learn to write questions that get honest, useful answers, from the field to the spreadsheet, in development work across South Asia.

Survey Fundamentals

Before writing a single question, you need clarity on three things: who you are asking, what you need to know, and how you will use the answers.

The survey design triangle

Weak foundation

"Let's do a survey about water." No clear objective, no defined population, no analysis plan. The results will be noise.

Strong foundation

"We need to measure household water insecurity in 3 drought-prone villages to target our tanker distribution." Clear, actionable, specific.

Start with the decision. A good rule: for every question, ask "what decision will this answer change?" If the honest answer is "none", cut the question.

Question types at a glance — tap a card

Multiple choice

Single or multiple select. Easy to analyse. Watch for overlapping or non-exhaustive options.

Likert scale

Agreement/frequency scales (often 5- or 7-point). Standardised and comparable. Watch acquiescence and midpoint bias.

Open-ended

Rich qualitative data. Resource-intensive to code. Use sparingly and with a clear coding plan.

Ranking

Forces prioritisation. Harder to analyse. Best kept to a short list of items.

Matrix / grid

Efficient for similar items. Risk of straight-lining. Break long grids into chunks.

Demographic

Age, gender, caste, income. Sensitive — always allow "Prefer not to say".

South Asia tip: In many rural settings, asking direct income questions tends to produce underreporting. Large household surveys such as India's NFHS instead build a wealth index from asset ownership (e.g. TV, two-wheeler, pucca house, land, cooking fuel). Asset-based measures are usually more reliable and less intrusive than a single income question. Method note

Writing Questions That Work

Bad questions produce bad data. Here are the most common survey-killers — and how to identify them.

Spot the bias. Below are survey questions modelled on real development projects. For each, identify the main problem. These items are teaching examples. Illustrative items

Scale Design & Response Options

Scales look simple, but small choices create big differences in data quality.

The 5-point vs 7-point debate

5-point scale

Simpler and faster to administer; often easier for low-literacy respondents. Less granularity than a longer scale.

7-point scale

More granularity and, in several methodological reviews, marginally higher reliability. But it adds cognitive load and can be harder to administer verbally.

What the evidence says: There is no single "best" number of points. Methodological reviews suggest scales with more than 5 points and an odd number of categories can yield slightly better reliability and validity, but the gains are modest and context matters far more — respondent literacy, mode (face-to-face vs self-administered), and translation all outweigh the 5-vs-7 choice. Pick the scale your respondents can use consistently.

Interactive: build your scale

Choose the parameters and watch the labels update.

Watch for response bias: Some respondents agree with almost anything (acquiescence bias) or gravitate to the midpoint (central-tendency bias). Balanced keying (an equal mix of positively and negatively worded items) helps curb acquiescence; a forced-choice scale can reduce midpoint clustering. And remember: "Don't know" is a legitimate answer — forcing a guess just adds noise.

Build Your Survey — Water Insecurity

You are designing a survey for a drought-affected village in Maharashtra. Draft a 5-question instrument using what you have learned. Illustrative scenario

Sampling, Bias & Ethics

A perfect questionnaire sent to the wrong people is still wrong data — and the wrong questions can cause real harm.

Sampling bias vs response bias: These are different problems. Sampling bias is about who ends up in your sample (a flawed frame or non-random selection). Response bias is about how people answer once selected (social desirability, acquiescence, recall error). A large sample fixes neither.

Sampling methods compared

MethodWhen to useMain risk
Simple randomA complete population list (frame) existsRare in field settings; frame is often incomplete
StratifiedNeed representation across caste / gender / wealthMore complex to design and implement
ClusterGeographically dispersed population; no full frameHigher design effect (larger sample needed)
PurposiveQualitative depth or specific expertiseNot statistically generalisable
SnowballHard-to-reach / hidden populationsNetwork bias — sample mirrors referral chains
Translation matters as much as sampling: If you survey across languages, translation quality shapes your data. Current best practice (WHO and the European Social Survey's TRAPD approach) favours a team-based translation, review and adjudication process with cognitive pre-testing in each language. Simple "back-translation" (translate out, translate back, compare) is a useful check but is no longer considered sufficient on its own — it can miss meaning shifts that back-translation happens to reverse.

Ethics: consent under India's DPDP Act, 2023

If your survey collects personal data digitally in India, the Digital Personal Data Protection (DPDP) Act, 2023 applies. Tick the safeguards you can honestly say your survey meets:

Common myth to unlearn: Unlike the GDPR (and India's older 2011 SPDI Rules), the DPDP Act, 2023 does not create a separate legal category of "sensitive personal data" with graded safeguards. It regulates all digital personal data under one framework, with extra protection specifically for children and persons with disabilities (Section 9). Ethically you should still handle caste, health and biometric data with special care — but do not cite a "sensitive data" tier that the Act does not contain. Not legal advice
Survey design includes survey conditions. A poorly protected interview can put respondents at risk. For example, questions on domestic violence asked without a genuinely private setting can be overheard by household members and lead to retaliation. Sensitive modules need a private space, trained enumerators, and a clear protocol for referral and safety. Illustrative example

Pilot, Iterate, Deploy

Never deploy a survey you have not tested. A good pilot catches problems that only look obvious in hindsight.

The pilot checklist

Quick readiness score

Check the boxes above, then calculate your pilot readiness.

Lab complete

You can now design survey instruments that produce clean, actionable data — and protect the people who answer them.

  • Start with the decision, not the question — every item must earn its place
  • Spot leading, double-barrelled, jargon-laden and loaded questions
  • Choose scales deliberately: 5- vs 7-point, neutral vs forced choice, and guard against acquiescence
  • Distinguish sampling bias from response bias, and translate with a team-based, cognitively tested process
  • Treat ethics and consent (DPDP Act, 2023) as part of design, not an afterthought
  • Pilot, iterate, and never deploy an untested instrument
Survey Design Questionnaire Bias Likert Scales Research Ethics South Asia

Recommended next steps