1. biased sample
sample not representative of the
entire population
2. convenience sample
sample members are selected
through the use of a rule
3. unbiased sample
sample where every member of the
population has an equal chance of being
selected
4. self-selected sample
sample where members volunteer
to take part
5. stratified sample
members are selected from the
different subgroups within a population
6. systematic sample
sample where representatives are
easily accessible