/survey-design

name: survey-design
description: Design unbiased survey instruments — question wording, scales, and sampling — to measure attitudes at scale. Use when you need quantitative breadth. For behavioural experiments, use `a-b-test-design` (prototyping-testing).

Survey Design

You are an expert in designing surveys that produce reliable, actionable data — not noise.

What You Do

You design surveys with well-formed questions, appropriate scales, and sound methodology so the data you collect can be trusted and used to make decisions.

When to Use Surveys

Surveys are quantitative research: they measure prevalence, frequency, and attitude at scale. Use them when:

• You need to know how many users share a need, problem, or opinion (not just whether some do)
• You need to validate or quantify findings from qualitative research (interviews, usability tests)
• You need to measure change over time (satisfaction scores, NPS trends)
• You need a representative sample across a population segment

Do not use surveys to discover problems you don't yet know exist — that's qualitative research's job. Surveys confirm and quantify; interviews explore and reveal.

Survey Structure

Introduction

• State the purpose: "We're improving [X] and want to hear your experience."
• State the time required: "This takes about 3 minutes."
• State anonymity/confidentiality if applicable
• No leading language — don't pre-frame what the "right" answers are

Question Order

1. Screen and demographic questions (if needed) — short, at the start 2. Behavioral questions (what users do) — before attitudinal questions 3. Attitudinal/satisfaction questions — after behavioral context is established 4. Open-ended questions — at the end; they require more effort and shouldn't fatigue respondents before the core questions

Closing

• Thank participants
• Provide a path to learn more or be contacted for follow-up (optional)

Question Types

| Type | Use for | Caution | |---|---|---| | Single-choice (radio) | Mutually exclusive options | Ensure options are exhaustive; include "Other" when needed | | Multi-select (checkbox) | Multiple applicable answers | Don't use when you need to rank or when options are mutually exclusive | | Likert scale | Attitudes, agreement, satisfaction | Use consistent scale direction (1=low, 5=high); always use labelled endpoints | | Rating scale (1–10, NPS) | Single-dimension measurement | Specify what each end means | | Ranking | Relative importance between items | Limit to 5–7 items; ranking is cognitively taxing | | Open text | Explanation, unexpected answers | Use sparingly; qualitative responses are expensive to analyze |

Question Writing

Avoid these patterns:

• **Leading questions**: "How much do you enjoy using our product?" → "How would you describe your experience using our product?"
• **Double-barreled questions**: "How easy and enjoyable is checkout?" → Split into two questions
• **Loaded language**: "How satisfied are you with our fast shipping?" → Remove "fast"
• **Recall overload**: "In the past 12 months, how many times…" → Shorter recall periods are more accurate
• **Jargon**: Use the same terms users use, not internal product names

Do these instead:

• One question per question
• Specific, behaviorally grounded language
• Mutually exclusive and collectively exhaustive response options
• Neutral phrasing that doesn't suggest a preferred answer

Scales

Likert Scales

• 5-point and 7-point are both defensible; 5-point is easier for respondents
• Always include a midpoint — don't force binary responses unless the question is genuinely binary
• Always label endpoints: "1 = Strongly disagree, 5 = Strongly agree"
• Be consistent with scale direction across the entire survey

Net Promoter Score (NPS)

• 0–10 scale; "How likely are you to recommend [product] to a friend or colleague?"
• Promoters: 9–10; Passives: 7–8; Detractors: 0–6; NPS = %Promoters − %Detractors
• NPS is a single, comparable metric — don't use it as a complete satisfaction measure

System Usability Scale (SUS)

• Validated 10-question scale for perceived usability
• Score 0–100 (68 is the average; above 80 is considered good)
• Use verbatim — don't modify the questions

Sampling

• **Sample size**: for a ±5% margin of error at 95% confidence in a large population, you need ~385 responses
• **Representativeness**: sample should match the demographic profile of the population you're studying
• **Response bias**: people who respond to surveys differ from those who don't — acknowledge this limitation
• **Survey fatigue**: keep surveys short (under 5 minutes); response quality drops significantly beyond 10–15 questions

Analyzing Results

• Report descriptive statistics: mean, median, distribution — not just "most people said X"
• For Likert data: show the full distribution, not just the average
• Open text: code themes; report top themes with example quotes
• Cross-tabulate by segment when segments differ meaningfully (new vs returning users, mobile vs desktop)
• Report response rate and sample size alongside every finding

Best Practices

• Pilot test with 3–5 people before sending — cognitive pretesting reveals confusing questions
• Keep surveys short; every question you add reduces completion rate and data quality
• Define your analysis plan before writing questions — "what decision will this answer?" for every question
• Pair with qualitative research: surveys tell you what and how many; interviews tell you why