Chapter 6
Surveys and Sampling
Surveys
• 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
people.
Surveys
• 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:
Telephone
Face-to-Face
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
Qualitative
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
Quantitative
Questionnaires
• 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
respondents
• May produce greater honesty from
respondents
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
payments
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
population
• 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.