Midterm Flashcards
What is a sampling frame?
A roster of individuals from which a sample is extracted; it’s a subset of the population.
What is undercoverage in sampling?
When members of the population are inadvertently omitted or excluded from the sampling frame.
What is sampling error?
The difference between the information a sample provides and the true population information.
What is non-sampling error?
An error caused by factors unrelated to the sampling process itself.
What is non-probability sampling?
Sampling that disregards probabilities of selection.
What is convenience sampling?
Individuals included simply because they are readily available.
What is simple random sampling (SRS)?
Also called randomized sampling; each member has an equal probability of selection.
What is systematic random sampling?
Involves choosing a random starting point and then selecting every kth person from the sampling frame.
What is quota sampling?
Ensures the sample accurately reflects specific traits of the population by collecting representative data from subgroups.
What is probability sampling?
Characterized by randomized sampling; every member of the population has a known, non-zero chance of being selected.
What is stratified random sampling?
Divides the population into various subgroups (strata) based on specific characteristics.
What is cluster random sampling?
Randomly selects clusters and then samples individuals within the selected clusters.
What is multistage random sampling?
Combines elements of cluster and other sampling techniques, creating gradually smaller groups at each stage.
What are the three key factors affecting sample size?
- Confidence Level: The degree of certainty that the population is correctly represented.
- Allowable Error (Margin of Error): The maximum error we can accept in our results.
- Population Standard Deviation: How much the values in a population vary.
What is the Raosoft calculator?
A sample size calculator used in survey research to determine the number of respondents needed to achieve a desired level of accuracy.
What is the sampling distribution of the sample mean?
A probability distribution made up of the means of all potential samples for a given sample size.
What does the Central Limit Theorem state?
If all samples of a particular size are selected from any population, the sampling distribution of the sample mean is approximately a normal distribution; this approximation improves with larger samples.
