Every member of the target
population has an equal chance of
being selected e.g by numbering
and listing all and using a random
number generator
STRENGTH
Likely to be unbiased as the
researcher does not control
who paricipates
WEAKNESS
Very hard to do unless you have a very
small population
STRATIFIED SAMPLING
PROCEDURE
The sample is a proportional
representation of the target population.
You break the population down into
groupsand recreate a smaller version e.g
males and females, or by age group
STRENGTH
Very represenatative of the population if done correctly
WEAKNESS
Time consuming and difficult
OPPORTUNITY SAMPLING
PROCEDURE
P's are selected from whoever is
available at the time e.g. whoevers in
class on the day you hold your study
STRENGTH
Easy, quick and most likely ethical
WEAKNESS
Probably not very representative, as
drawn from a small selection of the
communiy
VOLUNTEER SAMPLING
PROCEDURE
P's select themselves e.g. people
respond to advertisement
STRENGTH
Probably access a variety of
people you would not normally
have access to - likely to be
motivated
WEAKNESS
Motivation may make them
behave differently. Volunteers
may have special qualities