Improve data quality, obtain in-depth information about each subject. Want to minimize the number of things we examine or maximize the quality of our examination of those things we do examine.
Generalize the population to make better changes to society
When is sampling unecessary?
When the number of things we want to sample is small
Data is easily accessible
Data is unaffected by what we look at
What is an example of Sampling Frame?
An example of a sampling frame is a list of High School students
What is an example of elements/sample units in a sample?
The High School students name
What is an example of unit of analysis?
Once I have chosen a High School students name and am going to survey that student it becomes the unit of analysis.
What does Probability mean?
Every element of a population has a chance of being included.
Also random sampling
Less likely to be biased
What does Nonprobability mean?
Not every member of the population has a chance of being studied
Purposeful
Selected group
What are 3 types of Sampling Errors?
Coverage
Nonresponse
Sampling
What does coverage error mean?
The people that are left out
When results are different between the sampling frame and the target population
Example: not everyone has a phone, those without will be excluded from the sample but not on purpose.
What is a Nonresponce error?
When people do not answer the survey
No data can be collected from the individual
What is Sample Error?
Difference between the characteristics of a sample and the charactertics of the population from which the sample is drawn
Sampling Variability: Variability in sample stat occurs when different samples are drawn from the same population
What are the types of Probability Sampling?
Simple Random
Systematic
Stratified
Cluster
Multistage/Multicluster
What is Simple Random Sampling?
Write names on a paper and draw from hat
Use the number chart to pick people by the number
What is Sampling Distribution?
The distribution of a sample statistic
Distribution of any statistic tends to be around the population parameter, especially as the sample gets bigger (the more accurate)