Chapter 6

Chapter 6
Surveys and Sampling
• Survey – a series of self-report measures
administered through either an interview or a
written questionnaire.
• The most widely used method of collecting
descriptive information about a group of
• The goal of a survey, as with all descriptive
research, is to produce a “snapshot” of the
opinions, attitudes, or behaviors of a group of
people at a given time.
Survey by Interview
• Questions are read to a respondent:
Free-Format Interviews
• In an Unstructured Interview the interviewer
talks freely with the person being interviewed
about many topics.
• Focuses on topics the respondent is most
interested in or knowledgeable about.
Individual Respondents
Focus Groups
Open-Ended Questions
Fixed-Format Interviews
• Because researchers usually want more
objective data, the Structured Interview,
which uses quantitative fixed-format items, is
most common.
Highly Structured
All Questions Prepared Ahead of Time
Closed-Ended Questions
• A Questionnaire is a set of fixed-format, selfreport items that is completed by respondents
at their own pace, often without supervision.
• Less expensive than interviews
• Websites and Mail
• Appearance of greater anonymity for
• May produce greater honesty from
The Response Rate
• Response Rate – the percentage of people
who actually complete the questionnaire and
return/send it to the researcher.
• A low response rate may lead to incorrect
conclusions (different populations?)
• Some incentivize with gifts or monetary
Question Order
1. “How satisfied are you with your
relationships with your family?”
2. “How satisfied are you with your relationship
with your spouse?”
• If answered out of order…
• May lead to Measurement Error
Use of Existing Survey Data
• U.S. Census (every 10 years)
• General Social Survey (U.S. sample every year)
• Human Area Relations Files (International)
Sampling and Generalization
• Measure an entire Population to get a Census
• Measure a Subset of a Population and you
have a sample
Representative Sample
• A Representative Sample is one that is
approximately the same as the population in
every important respect.
Simple Random Sampling
• For Simple Random Sampling, the goal is to
ensure that every person in the population
has an equal chance of being selected to be in
the sample.
• Need a complete list of everyone in the
• Use random number generator
Sampling Bias
• Sampling Bias – occurs when the sample is
not actually representative of the population
(because the probability with which members
of the population have been selected for
participation is not known).
Snowball Sampling
• A few population members are contacted, and
these individuals are used to lead the
researcher to other population members.
• Homeless
• Underground Groups
Convenience Samples
• Whomever is readily available.

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