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Writing Surveys that Work
UX Brown BagRebecca Weiss, Metrics Team
About this talk
What this talk is about:
• The main concepts in surveys and questionnaires
• Some “best practices” and general principles
• There’s no way we can cover everything (not even a Ph.D. covers everything)
What this talk isn’t about:
• Statistical methods
• Sampling theory
• Scholarly literature
What you should get from this talk:
• The ability to constructively critique questionnaires
• The perspective needed to do better survey research
What is a survey?
1.Census != Surveys
Census: an entire population
Survey: a sample representing a population
2.Surveys != Questionnaire
Surveys: highly structured process of measuring self-reported attitudes, opinions, beliefs, habits, behaviors of a population via a sample
Questionnaire: instrument used in surveys that is distributed to the sample
Survey issues
Sampling
Who is the population? Is it possible to use the whole population? If not, how am I sampling? Is my method representative?
Design
Are all respondents getting the same survey? Or do I have multiple conditions?
Analysis
What are the data going to look like? How should I use counts or proportions? Are my results statistically significant?
Survey issues
A talk for another time, perhaps!
Questionnaire issues
Question wording
Have I written this question using unambiguous language? Will every word be understood the same way by every respondent?
Response methods
What options should I give to the respondent? Should I use scales? Agree-disagree? Open-endeds? Should I include no opinion/neutral?
Question ordering
Does it matter which order I put my questions or response options?
The Construct
Constructs are theoretical variables that you can’t measure directly
• Examples: user satisfaction, attitude toward the mission
The questionnaire is the instrument used to measure constructs through observed variables
• Examples: Likert scales, feeling thermometers
Always consider the following: is my construct valid? Am I asking respondents questions that are accurately measuring this construct?
The Construct
Some things to think about your construct:
•What’s the polarity? Does it have valence?
•How would I describe its continuum?
•What’s the dimensionality?
Questionnaires: Wording
If respondents don’t understand your question in the exact same way and can’t respond equally easily, you will get measurement error.
“Which of the following changes to Firefox would have the most impact
on your experience?”Vocabulary ambiguity
Questionnaires: Wording
If respondents don’t understand your question in the exact same way and can’t respond equally easily, you will get measurement error.
“Did you know that Mozilla is a mission-driven organization to make
the Internet a better place?”Double-barreled
Questionnaires: Wording
If respondents don’t understand your question in the exact same way and can’t respond equally easily, you will get measurement error.
“Would you say that mobile Firefox is better than any other mobile browser available on the
market?”Lack of balance
Questionnaires: Wording
If respondents don’t understand your question in the exact same way and can’t respond equally easily, you will get measurement error.
“How strongly do you agree or disagree that Mozilla is a positive force for Internet
privacy?”Prone to cognitive bias
Questionnaires: Wording
If respondents don’t understand your question in the exact same way and can’t respond equally easily, you will get measurement error.
“Rank these 20 features in order of most useful to least.”Prone to satisficing
Questionnaires: Responses
1.Make it as easy as possible for every respondent to respond!
2. The response options should map as closely to the construct’s continuum as possible.
Questionnaires: Responses
“Can I use a rating scale?”
Unipolar measure = 5pt scale (e.g. “Not at all -> All the time”)
Bipolar measure = 7pt scale, with neutral point (e.g. “Strongly agree-Strongly disagree”)
Questionnaires: Responses
“Should I enumerate my options or fully-label them?”
Fully-labeled, non-enumerated options for scales have been shown to be the most reliable.
Remember, one respondent’s “3” might not be the same as another’s!
Questionnaires: Responses
“Should I include “don’t know“/ “no opinion” / neutral points?”
Pro: You may get more accurate responses from low knowledge respondents (or ones without opinions)
Con: You may see increased satisficing
Questionnaires: Responses
“Can I use ranking?”
Only with a few items, and only if you think all respondents will be able to clearly distinguish between all options.
What if most respondents don’t care about almost all of
your options?
What if they can’t choose the third most important item between three different options (equally important)?
Most importantly, how are you going to do your analysis?
Questionnaires: Responses
“Can I use agree-disagree?”
Think about the eventual distribution of responses to these questions; it is almost always easier to agree than to disagree with statements.
It is harder to evaluate from a negative frame than a positive, so flipping the valence of a question might not help.
There are, however, exceptions.
Questionnaires: Responses
“Should I ask for specific quantities?”
Humans are not very accurate at any quantitatively specific.
Stick to intervals and natural frequencies (1/10, not 10%) as much as possible.
Questionnaires: Responses
“What kind of options should I use for habitual or behavioral
questions?”
Humans are also bad at remembering their previous habits or behaviors.
Use average time periods, e.g. “In an average day/week/month…”
Questionnaires: Responses
“When should I use open-ended questions?”They are great for exploratory but not confirmatory research
They are also useful if you don’t want to bias your respondents towards choosing options that they haven’t seen before
“How many open-ended questions can I use?”
Thoughtful, deliberative responses are extremely taxing cognitively.
If you want a good response rate, never make them mandatory.
If you must, use them sparingly. No more than 1-3, and try not to put them together.
Questionnaires: Ordering
Why should I care about the order of questions or responses?
Questions might have spillover influence on future responses:
The answer to question x might affect responses to question x + 1…n.
This is why demographic questions tend to put at the end of questionnaires.
Response option ordering might skew your distribution:
People tend to focus more on earlier or later options, and spend less time evaluating middle options (primacy or recency effects).
One way to protect against ordering effects: randomization
Blocks of questions: randomize between blocks and/or within blocks
Response options: ranking, list ordering, polarity
A few examples
A few examples
A few examples
A few examples
Best Practices1.Always write down your research goal. You should write it down in 2-3
sentences so that a stranger can understand it.
2.Verify that you can’t achieve your research goal through behavioral measures.
3.Try to make your research questions as clear as possible. This makes it easier to write your questionnaire to directly address your questions.
4.Work with at least one other person in creating your questionnaire.
5.Pretest your survey with naïve respondents.
6.Always think about the distribution of responses!
7.Don’t put too much emphasis on statistical significance. Remember, you can make anything significant with enough respondents.
8.Most importantly, it’s questionnaire design not engineering. These aren’t rules, but guidelines to get better results!