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What is a survey instrument?
• For interviews: A script for interviewers, including introductions, instructions, and questions
• For self-administered surveys: A questionnaire
What is the worst thing you can do?
• Jump in without thinking about purpose of study, objectives, analysis plan!
• Think first, start slowly!
Essential steps in developing a survey instrument
• Statement of purposes– What do you want to accomplish with the
survey? Research questions, objectives
• List of the variables to be measured– Group into logical categories
• Draft analysis plan– What are your dependent, independent
variables? What are potential confounders?
Design/variable grid
Research question
Dependent variables
Independent variables
Potential confounders
Are clients satisfied with ancillary services?
Satisfaction with individual services (yes/no)
Gender
Race
Ethnicity
Age
Disease status
Pregnancy
Children
Need for services at baseline
CD4 count
Viral load
Medication status
Satisfaction with individual services (scale)
Etc.. Etc..
Preliminary question design steps
• Interdisciplinary research group– What are the research questions/
objectives/hypotheses?
• Focus groups
• Draft questions• Cognitive laboratory interviews
• Pilot/pre-test
Focus groups (1)
• Objective: To compare the reality about which respondents will be answering questions with the abstract concepts embedded in the study objectives
• Usually 6-8 people per group; have a couple of groups
Focus groups (2)
• Try to get participants who are similar to your survey population
• Talk about perceptions, experiences, and feelings related to survey subject
• Get people who are experts in focus group leadership
Drafting questions
• Look for standard questions from other surveys– Benefit from their experience– Enhance comparability of your survey with
previous surveys
• Write good questions
• Don’t remake the wheel!
Cognitive laboratory interviews
• Respondents are brought into a laboratory setting– May be videotaped– Interviews conducted by cognitive
psychologist or experienced investigator
• Goal: To get information about how the respondent understood the questions and about the way they answered them
Layout of survey instrument
• Make it clear and simple
• Usually begin with straightforward questions, put complicated or sensitive questions in the middle or at the end
Interviews
• Should have everything scripted, including introductions, instructions, transitions, definitions, and explanations
• Be very explicit about skip instructions
• Differentiate instructions and optional wording from questions– Usually done with all caps and
parentheses, respectively
Example
Interviewer instructions: … read aloud all sentences that are in bold. Italics indicate instructions for interviewer that are not to be read aloud…
Have you been pregnant in the last three (3) months?
� 1—yes [if yes, skip to question 4]� 2—no [if no, skip to question 5]
Self-administered
• Questionnaire should be self-explanatory (minimal instructions needed)
• Limit to closed questions
• Use short questions with consistent formats
• Minimize skips; make them very clear
Example
Instructions: Please make a check () in the box which best reflects your answer.
Have you been pregnant in the last three (3) months? � 1—yes Did you take a
prenatal vitamin? � 1—yes � 2—no
� 2—no Did you take a multi-vitamin? � 1—yes
� 2—no
*Note problems with these questions!
Field pre-testing
• Goal: Find out how well the data collection protocols and survey instruments work under realistic conditions
Interviews
• Usually interview 20-50 respondents who are similar to your survey population
• Interviewers note ways to improve survey instruments
Quantitative methods for pre-testing (1)
• Ask interviewers to fill out a rating for each question– Is it easy to read as worded?– Do respondents understand the question in
a consistent way?– Can respondents answer the question
accurately?
• Note problems possible in interpreting if that survey isn’t good…
• Taping and behavior coding– Trained coders review the recordings and
evaluate the question and answer process in a consistent way
• Do the interviewers read the question as worded?
• Do the respondents ask for clarification?• Do the respondents initially give an inadequate
answer that requires interviewer probing?
Quantitative methods for pre-testing (2)
Self-administered
• Have respondents (who are similar to your survey population) fill out the survey and then discuss– Were the instructions clear?– Were the questions clear?– Were there any problems understanding
what kind of answers were expected?
Validity and reliability
• If you are developing this tool, find ways to undertake testing of validity and reliability (crudesophisticated)
• Note difficulties with this, and benefits to using already-validated tool
Open-ended questions• Short, specific
– What is your current age?
• Long, narrative– Why did you choose to come to this clinic?
• Problems:– Illegible handwriting– Inappropriate detail
• Usually avoid-the rest of the lecture is devoted to closed-ended questions
Yes/No and checklist questions
• Yes/No
• Checklist– From a list of alternatives, check those that
apply– Problematic because you can’t distinguish
a “No” from a skip– Yes/No may be better because it forces
thought
Multiple-choice questions• Response alternatives should be mutually
exclusive and exhaustive• Think about whether you want respondents to
just check one response or to be able to check multiple responses– Multiple responses may complicate analysis– Think about presenting alternatives as a checklist
Multiple-choice questions (2)
• Include “Other” as an alternative?– What does it tell you?
• About the respondent?• About your question?
– Use open-ended “Specify”________– May be useful during pretesting or if you
are planning on revising the survey instrument
Semantic differential questions
• Two opposite adjectives at the ends
Best Worst
1 2 3 4 5 6 7
• Sometimes ask the question for two scenarios, ex: current situation and ideal situation, and look at the differential
Ranking questions
• Present alternatives and ask respondents to rank them– Ex: rank from the most important to the
least important
• Think about whether you want to allow tie rankings– How will that affect your analysis?
Two common formats
1
__ Eating fruit
__ Exercising
__ Meditating
__ Being happy
__ Sleeping enough
2
Eating fruit 1 2 3 4 5
Exercising 1 2 3 4 5
Meditating 1 2 3 4 5
Being happy 1 2 3 4 5
Sleep enough 1 2 3 4 5
Number 2 is usually preferable. Why?
Rating Scales• Present a respondent with a question or
statement and a range of responses
• Ex. How would you rate your relationship with your physician?
Excellent Very good Good Fair Poor
Rating scales (2)
• Likert scale:
Ex. Patients should have the right to sue Health Maintenance Organizations
Strongly Agree Unsure Disagree Strongly agree disagree
Rating scales (3)
• Psychological distance– Distance between alternatives should be
equal
• Number of response alternatives– Usually 3 to 7 are recommended– What might affect your choice?– Think about your research question– Think about the complexity of the issue
Rating scales (4)
• Order of response alternatives– Should be monotonically increasing or
decreasing– Should all be ordered in a column or row– Within a survey, may want to mix up
increasing and decreasing by section, but never within a section
Rating scales (5)
• Unipolar response alternatives– Range from “nothing” to “a great deal”
Excellent Very good Good Fair Poor
• Bipolar response alternatives– Range from “large negative” through “zero”
to “large positive”Strongly Disagree Unsure Agree Strongly
disagree agree
Rating scales (6)
• Odd or even number of alternatives?– Odd numbers create a midpoint
• This midpoint should be a neutral response• Many respondents really like midpoints and will
use them a lot!!!
– Even numbers force people to make a decision
– Depends on your research question
Rating scales (7)
– For very complex, emotional issues, you may want to have 2 middle points
• Ex. Slightly agree and Slightly disagree
• Balanced scales– Should have equal numbers on either side
of neutral – Unbalanced scales will lead to bias
Rating scales (8)
• “Don’t know” as an alternative– Usually necessary for knowledge questions– For attitude questions, “don’t know” usually
means “unsure”. Adding more middle categories may be a better solution
– Sometimes use a screen question then initiate a skip sequence
Rating scales (9)
• Example of a screening question:1. Are you familiar with the proposed legislation
regarding universal healthcare?
(circle one)
Yes Go to question 2.
No Go to question 17.
Rating scales (10)
• Behaviorally anchored scales– Objective, quantitative– Compare to subjective scales
Ex: How often do you exercise in a week?
• Subjective: Often Sometimes Never
• Behaviorally anchored: 5 times 3-4 times 1-2 times Never
• Which one to use?– Depends on your research question
General Recommendations• Write brief questions• Write clear questions
– Define ambiguous terms– Avoid jargon– Avoid double negatives– Avoid unclear pronouns– For open-ended questions, avoid adverbial
constructions such as how, why, when, where
General Recommendations (2)
• Be careful with:– Intentions– Hypotheticals– Assumptions: commonplace is not
universal
• Write unidimensional questions • Write mutually exclusive and exhaustive
response alternatives
General Recommendations (3)
• Generally avoid loaded questions– Special case for questions that may involve
social desirability– When might we want to ask loaded
questions?
• “Most people have times when they drink too
much and feel tipsy. How often has this happened to you in the last month?”
• “Most people feel that smoking marijuana is harmful. How do you feel?”
• “Marijuana has been shown to be an effective treatment for people with some symptoms of AIDS. How do you feel about legalizing marijuana?”