Chapter 7 - Sampling Flashcards
Population
The integral collection of people or things you are interested in
Census
If you include every member of the population in your survey
Sample
A subset of people or things, taken from the population
What is a biased sample?
Certain individuals have a greater chance of being in the sample than others
What are the two ways of having a biased sample?
Convenience sampling
Self selection
Convenience sampling
Only easily accessible people are included in the sample
Self selection
Only conduct surveys with people who are attracted to it
Eg: online polls
What are the different ways of having a representative sample?
Simple random sampling
Cluster sampling
Stratified sampling
Oversampling
Systematic sampling
Simple random sampling
Give everyone in the population a number, for example, and then draw random numbers
Cluster sampling
When there are already randomly distributed groups use the people in one or more clusters
Multisage sampling
Two random samples are selected
A random sample of clusters and a random sample of people in these clusters
Stratified sampling
The researcher selects a specific demographic category and randomly selects individuals within these categories
Oversampling
Deliberately over representing a certain group
Systematic sampling
A random number table is set up by means of a computer
The researcher chooses a few numbers and takes for example every 4th peon who enters a room or by rolling dice
Start with the 5th child and then take every 3rd child
