Simple Random
Members are chosen using a method that gives everyone an equally likely chance of being selected
Systematic
Members are chosen using a pattern, such as selecting every other person
Stratified
The population is first divided into groups. Then members are randomly chosen from each group
Cluster
Divide the population into logical groups, then select ALL of the members of that "cluster"
Convenience
Members are chosen because they are easily accessible
Self-Selected
Members volunteer to participate
Underrepresented
One or more of the parts of the population are left out when choosing the sample
Overrepresented
A greater emphasis is placed on one or more parts of a population when choosing a sample