Chapter 11- Determining Sample Size Flashcards
What are the factors that influence sample size?
variation in what you’re measuring, importance of the decision you’re trying to make, resource constraints, number of variables, nature of the research (Descriptive vs. Exploratory)
Which form of research can usually use a smaller population?
Exploratory research
Is population related to the sample size?
No
small population guidelines: how big of a sample would you need to have with a population of 1000?
517
small population guidelines: how big of a sample would you need to have with a population of 500?
341
small population guidelines: how big of a sample would you need to have with a population of 300?
235
small population guidelines: how big of a sample would you need to have with a population of less than 300?
Everyone (census)
What are the two approaches for determining sample size?
Financial/managerial criteria (non-probability sampling) Statistical techniques (probability sampling)
As a rule of thumb, how big of a sample size should you take from a main group?
Minimum of 100 per group
As a rule of thumb, how big of a sample size should you take from a subgroup?
Minimum of 50 per subgroup
Are statistical approaches used for non-probability sampling?
No only probability sampling
In statistical analysis what are the three main things that you need to know?
Decision makers desired margin, confidence level required, and variance of the characteristics being measured
Does the margin of error continue to change as you increase the sample size?
No, once you reach a certain amount in your sample size the margin of error doesn’t change
If there is more variability in the population is the sample size larger?
Yes
Which form of research can usually use a smaller population?
Exploratory research
