Exam 2: Sampling Flashcards
What is a population in research?
The entire set of people or products in which a researcher is interested.
What is a sample?
A smaller subset taken from a population for study.
What is a biased sample?
A sample where some members have a higher chance of being selected than others.
Causes: only sampling those who are easy to contact, or able to be contacted at all, or only those who invite themselves
What is a representative sample?
A sample where all members of a population have an equal chance of being included.
What is probability sampling?
Also called random sampling; every member of a population has an equal chance of selection.
cluster and multi-stage sampling
What is stratified random sampling?
A sampling method where researchers select a certain demographic category and then randomly sample within that category.
What is convenience sampling?
A non-representative sampling method where researchers sample those easiest to access.
What is snowball sampling?
A non-representative sampling method where participants recruit others, often used for hard-to-reach populations.
Does a bigger sample always mean better results?
No, the method of selection is more important than the sample size.
oversampling
A variation of stratified random sampling.
Intentionally overrepresent one or more groups and then weight them in the final analysis
simple random sampling
Draw names out of a hat where whole population is included
Random number generator/computer program
systematic sampling
Pick two numbers at random
is random assignment the same as random sampling?
NO
Random sampling enhances external validity
Random assignment enhances internal validity
cluster sampling
a probability sampling method in which a population is divided into groups (clusters), and a random selection of entire clusters is studied instead of selecting individuals directly.
