Surveys

Outline

1. Definition

2. When and why to use surveys

3. How to create a survey

Surveys

Surveys - Definition

• A survey is a procedure for systematically collecting information about attitudes, preferences, knowledge, or behavior by asking people questions.

Surveys

When to Use Surveys

• When you want information about a population, but you cannot measure the whole population.

• It is usually the case that you cannot measure whole population

• Doing so is unnecessary

Surveys

Survey research - Definition

• Survey research has 3 major characteristics:

• Asking people questions using a formal procedure

Surveys

Survey research - Definition

• Survey research has 3 major characteristics:

• Using a quantitative method that requires standardized information as input

Surveys

Survey research - Definition

• Survey research has 3 major characteristics:

• Generalizing results from sample to population it was drawn from

Surveys

When to Use Survey Research

• Two distinct forms of survey research:

• Exploratory

• Used in new research areas where little theory has developed

• “descriptive”

Surveys

When to Use Survey Research

• Two distinct forms of survey research:

• Exploratory• Explanatory

• Looking for evidence of cause-effect relations among variables

• “If C causes D, then C and D should be correlated.”

Surveys

Advantages of survey approach

• Surveys are:

• Cheap

• Relative to measuring whole population

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Advantages of survey approach

• Surveys are:

• Cheap• Practical

• Can be done in a short time

• Can be done over phone or through mail or internet

Surveys

Advantages of survey approach

• Surveys are:

• Cheap• Practical• Accurate

• Results true of population within a small margin of error

Surveys

Margin of Error

• A range of values• True population value is

likely to be in this range.• If range is large, survey

results are not useful

• Size of range depends upon sample size and confidence level chosen for estimating population value.

Value obtained from sample

Margin of error = range of valueswhich containspopulation value

%

Surveys

How to create a survey

• Research questions• Design• Survey questions• Sampling procedure• Administration procedure• Analyzing the results

Surveys

Research question

• Start with a behavioral theory.

• Use it to generate research questions.

• Specify type of information that will (or won’t) meet your scientific objectives

Surveys

Research question

• Be as specific as possible• Think about interpretation

• In reports, you won’t discuss the actual questions on your survey instrument – you’ll discuss some theoretical construct

• What is it?

Surveys

Design

Longitudinal • Same samples measured at different times

• Potential problem with loss of subjects

Surveys

Design

• Longitudinal• Cross-sectional

• One or more samples measured at one time

• If groups differ, it’s difficult to say why

Surveys

Design

• Longitudinal• Cross-sectional• Successive independent samples

• Different samples at different times

• Samples supposed to be drawn from same population – but that may be arguable if interval is long

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Survey questions

• If a survey exists that does the job, use it

• Otherwise…

• Write a first draft

Surveys

Survey questions

• If a survey exists that does the job, use it

• Otherwise…

• Write a first draft• Get feedback and

revise draft

Surveys

Survey questions

• If a survey exists that does the job, use it

• Otherwise…

• Write a first draft• Get feedback and

revise draft• Pretest your

questionnaire

Surveys

Survey questions

• If a survey exists that does the job, use it

• Otherwise…

• Write a first draft• Get feedback and

revise draft• Pretest your

questionnaire• Edit questions

Surveys

Survey questions

• If a survey exists that does the job, use it

• Otherwise…

• Write a first draft• Get feedback and

revise draft• Pretest your

questionnaire• Edit questions• Formalize procedures

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Survey questions

• Avoid bias • “Do you believe in killing unborn babies?”

• “Should women be forced to bear unwanted children?”

Surveys

Question from an ABC poll

• “Schiavo suffered brain damage and has been on life support for 15 years. Doctors say she has no consciousness and her condition is irreversible. Her husband and her parents disagree about whether she would have wanted to be kept alive. Florida courts have sided with the husband and her feeding tube was removed on Friday. What's your opinion on this case - do you support or oppose the decision to remove Schiavo's feeding tube?”

Surveys

A Gallup Poll question the same week

• “As you may know, on Friday the feeding tube keeping Terri Schiavo alive was removed. Based on what you have heard or read about the case, do you think that the feeding tube should or should not have been removed?” 

Surveys

Fox News poll 18 days earlier

• “Terri Schiavo has been in a so-called 'persistent vegetative state' since 1990. Terri's husband says his wife would rather die than be kept alive artificially and wants her feeding tube removed. Terri's parents believe she could still recover and want the feeding tube to remain.  If you were Terri's guardian, what would you do? Would you remove the feeding tube or would you keep the feeding tube inserted?”

Surveys

Issues

• Is “requiring tube feeding” the same as “being on life-support”?

• What does the public understand from the term “life-support”?

• Does the term bias the result?

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Issues

• Were results influenced by fact poll conducted in one evening?

• Were results influenced by whether the person involved was referred to as “Schiavo” or “Terri”?

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Survey questions

• Be careful about social desirability

• Think about question sequence

• Use filter questions

Surveys

Survey questions

• Don’t write two questions as one

• What would “No” mean in answer to this question:

• Do you support the Administration’s decisions to increase class sizes and start classes earlier in the day?

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Survey questions

• Do the people you’re surveying have the information required to answer your questions?

• Check to see before you ask your questions

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Survey questions

• “Are you familiar with the Liberal Party’s platform for this election?”

before

• “In your view, will the Liberal Party’s platform produce positive or negative effects on the economy?”

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Survey questions

• Is the meaning of your question clear?

• If you refer to “young people” do you mean 9 year olds? 25 year olds?

Surveys

Survey questions

• Is the meaning of your question clear?

• “Which newspaper do you read?”

• Does this mean everyday? Sometimes?

• What if the respondent reads more than one?

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Survey questions

• Is the meaning of your question clear?

• Be clear about the time frame of the behavior you are asking about

• E.g., CFQ asks about frequency of mental slips over the last six months

Surveys

Sampling procedure

• Major task: to select a representative sample

• Representative sample – shares distribution of relevant characteristics with population

Surveys

Sampling procedure

• Some technical terms you need to know

• Population• Sampling frame• Sample• Element

Population

Sampling frameSample

Element

Surveys

Types of sampling procedure

• Non-probability sampling

• Elements vary in probability of being chosen

• Those probabilities are not known

• Accidental samples• Purposive samples

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Types of sampling procedure

Non-probability sampling

Probability sampling

• Researcher knows the probability of inclusion for each element in population.

• Simple random sampling

• Stratified random sampling

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Administration procedures

• Phone • Cheap & fast• But who is home?• Verbal instructions

and response alternatives may be hard to remember

Surveys

Administration procedures

• Phone• Face-to-face

• Expensive• But maximal control• Interviewer can see

whether respondent understands question

• Respondent may work harder

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Administration procedures

• Phone• Face-to-face• Mail

• Inexpensive• Significant problem

with response bias

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Analyze the Results

• Select a data analysis procedure before you collect data.

• Correlations• Path analysis• Factor analysis