PSYCH 209 Lecture Notes - Lecture 10: Criterion Validity
27 Apr 2018
School
Department
Course
Professor
4/18/18 Lecture Notes: Surveys and Observations -
Sampling
A researcher is developing a new self-report measure of a person's tendency to say what's on their mind
as soon as they think of it. Which of the following would best help to establish the criterion validity of
this measure?
• Evaluating how known groups of people score on this measure, such as salespersons vs. librarians
Encouraging Accurate Responses
• Response sets
o Acquiescence (yea-saying/nay-saying)
o Fence sitting
o Solution
• Switch order of questions or ask the opposite question and see if they continue to say
yes or no
• Eliminating the neutral option for fence sitting
• Socially desirable responding and "faking bad"
• Saying more than we can know
o E.g., Nisbett & Wilson (1977)
o Confidence-accuracy correlation
Sampling: External Validity
Population vs. Sample
• Population
o The group or category of people or observations about which you would like to make claims
• "A population" vs. "the population"
• Sample
o The actually observed group that you can describe directly, and from which you can draw
broader inferences (about a population).
• A sample is biased if it differs systematically from the population you'd like it to
represent
• As the sample size is larger, you can get a better sense
Common Sources of Sampling Bias
• Convenience
o Sampling only people who are easy to reach
• Self-selection
o Sampling only volunteers
Nonprobability Sampling
• Convenience Sampling
o A researcher doesn't have funds to compensate participants, but there is a large pool of
people at her university who are eligible to receive course credit for participating in research
• Quota Sampling
find more resources at oneclass.com
find more resources at oneclass.com
