Chapter 9 Flashcards
What are the different types of probability sample and nonprobability samples
Non probability: Convenience, Judgement (Snowball) Quota
Probability Sample: Simple Random, Systematic, Stratified, Cluster
Describe the procedure in taking different types of probability and nonprobability samples
Define The Target Population, Identify the Sampling Frame, Select a Sampling Procedure, Determine the Sample Size, Select the Sample Elements, Collect the Data
What factors must be considered in determining the sample size?
Amount of Diversity or Variation
As diversity/variation increases, larger samples are required
Degree of Precision
As need for precision increases, larger samples are required
Degree of Confidence
Confidence increases as sample size increases
How does desired precision influence the sample size?
The degree of acceptable error in a study
How does the population diversity influence the sample size?
The more similar the population elements, the few people needed regardless of how large the population is
How does the desired confidence level influence the sample size?
The degree to which one can feel confident that an estimate approximates the true value
What are the non-statistical approaches in determining the sample size?
Size of research budget
Anticipated analysis
Past Studies
When does the population size become a factor in determining the sample size?
When theres a big diversity
Snowball Sampling?
Initial sample chosen by a probability technique (e.g., systematic sampling) then the population elements are asked for referrals of others they know who might be interested in participation
Example – A demand study for a new product where initial respondents know people with a high interest level within the product category
Stratified Sample
Sample in which (1) the population is divided into mutually exclusive and exhaustive subsets and (2) a simple random sample of elements is chosen independently from each group/subset
