Date post: | 13-Dec-2015 |
Category: |
Documents |
Upload: | duane-heath |
View: | 214 times |
Download: | 0 times |
Outline
1. Definition2. Three major characteristics3. When and why to use surveys4. Two distinct forms of survey research5. Advantages of survey research6. How to create a survey
Surveys - Definition
• A survey is a procedure for systematically collecting information about attitudes, preferences, knowledge, or behavior by asking people questions.
Three major characteristics
• Survey research has 3 major characteristics:
• Procedure• Analysis• Interpretation
Three major characteristics
• Procedure • Survey research involves asking people questions using a formal procedure
Three major characteristics
• Analysis • Survey research uses a quantitative method requiring standardized information as input• The formal procedure produces standardized information
Three major characteristics
• Interpretation • Survey research generalizes results from a sample to the population it was drawn from
When to Use Surveys
• When you want information about a population, but you cannot measure the whole population.
• Measuring the whole population is usually impossible
• Doing so is also usually unnecessary
2 distinct forms of survey research
• Exploratory • Used in new research areas where little theory has developed
• “descriptive”
2 distinct forms of survey research
• Explanatory • Looking for evidence of cause-effect relations among variables
• “If C causes D, then C and D should be correlated.”
Advantages of survey approach
• Surveys are:• Cheap
• Relative to measuring whole population
Advantages of survey approach
• Surveys are:• Practical
• Can be done in a short time
• Can be done over phone or through mail or internet
Advantages of survey approach
• Surveys are:• Accurate
• Results true of population within a small margin of error
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
%
How to create a survey
• Research questions• Design• Survey questions• Sampling procedure• Administration procedure• Analyzing the results
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
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?
Design
Longitudinal • Same samples measured at different times
• Potential problem with loss of subjects
• Do differences across time reflect change in society or change specific to subjects?
Design
• Cross-sectional • One or more samples measured at one time
• If groups differ, it’s difficult to say why
• E.g., compare 20 year olds to 50 year olds – do results differ because of age or because of cohort effect?
Design
• 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
• This design cannot measure change in individuals
Survey questions
• If a survey exists that does the job, use it• Otherwise…
• Write a first draft
Survey questions
• If a survey exists that does the job, use it• Otherwise…
• Write a first draft• Get feedback and revise
draft
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
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
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
Survey questions
• Avoid bias • “Do you believe in killing unborn babies?”
• “Should women be forced to bear unwanted children?”
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?
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?
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?
Issues
• Does requiring tube feeding mean the same as being on life-support?
• What does the public understand from the term life-support? Does the term bias the result?
Issues
• Were results influenced by fact ABC poll was conducted in one evening?
• "Surveys conducted on one evening, or even over two days, have more sampling biases -- due to non-response and non-availability -- than surveys which are in the field for three, four or five days.“
• National Council on Public Polls (NCPP)
Issues
• Were results influenced by whether the person involved was referred to as “Schiavo” or “Terri”?
Survey questions
• Be careful about social desirability
• Think about question sequence
• Use filter questions
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?
Survey questions
• Do the people you’re surveying have the information required to answer your questions?
• Check to see before you ask your questions
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?”
Survey questions
• Is the meaning of your question clear?
• If you refer to “young people” do you mean 9 year olds? 25 year olds?
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?
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
Sampling procedure
• Major task: to select a representative sample
• Representative sample – shares distribution of relevant characteristics with population
Sampling procedure
• Some technical terms you need to know
• Population• Sampling frame• Sample• Element
Population
Sampling frameSample
Element
Types of sampling procedure
• Non-probability sampling • Elements vary in probability of being chosen
• Those probabilities are not known
• Accidental samples• Purposive samples
Types of sampling procedure
Non-probability samplingProbability sampling
• Researcher knows the probability of inclusion for each element in population.
• Simple random sampling• Stratified random sampling
Administration procedures
• Phone • Cheap & fast• But who is home?• Verbal instructions and
response alternatives may be hard to remember
Administration procedures
• Phone• Face-to-face
• Expensive• But maximal control• Interviewer can see
whether respondent understands question
• Respondent may work harder
Administration procedures
• Phone• Face-to-face• Mail
• Inexpensive• Significant problem with
response bias
Analyze the Results
• Select a data analysis procedure before you collect data.
• Correlations• Path analysis• Factor analysis