1.2 Vocab - Random Samples Flashcards
What is a Simple Random Sample?
A subset of the population selected in such a manner that every sample of size n from the population has an equal chance of being selected.
What is a stratified sampling?
Divide the entire population into distinct subgroups called “strata”. Based on specific characteristics (age, income, edu. levels, etc.). Draw random samples from each groups. We do this when we think a characteristic will effect the results.
What is systematic sampling?
Number all members of the population sequentially. Then, from a random starting point, include every Kth member of the population in the sample.
What is cluster sampling?
Divide the population into pre-existing segments (clusters), often geographic. Make a random selection of the clusters and do a census on each selected cluster.
What is multistage sampling?
Use a variate of sampling methods to create successively smaller groups at each stage.
What is convenience sampling?
Create a sample by using data from population members that are readily available. - biased
What is undercoverage?
Results from omitting population members from the sample frame
What is a sample frame?
The list of individuals from which a sample is actually selected
What is sampling error?
The extent that sample information does not match the corresponding population - error
What is a non-sampling error?
The results of poor sample design, sloppy design, sloppy data collection, faulty measuring instruments, bias, ect.
Identify the sampling technique:
You divide the student population with respect to majors and randomly select and question some students in each major
Stratify
Identify the sampling technique:
You assign each student a number and generate random numbers. You then question each student whose number is randomly selected
Simple Random Sampling
Identify the sampling technique:
You select students who are in your history class
Convince
Identify the sampling technique: You want to determine the opinions of students regarding stem cell research. you select a class at random and question each student in the class.
Cluster
Identify the sampling technique:
You want to determine the opinions of students regarding stem cell research. You assign each student a number and, after choosing a starting number, question every 25th student.
Systematic
