Sampling Techniques Flashcards
What is random sampling?
Random sampling is when every member of a population has a chance of being selected for a sample
strength(s) of random sampling
.Unbiased
.potentially if the population is diverse enough, should produce a representative sample
Limitation(s) of random sampling
.There is still a chance the sample could be unrepresentative, for example all men.
What is systematic sampling?
A method of selection from a population by selecting at regular intervals. For example, every 3rd (Nth) person
Strengh(s) of systematic sampling
.very efficient, therefore convenient
Limitation(s) of systematic sampling
.a characteristic could become over-represented.
What is stratified sampling?
A method of selection by sorting people into sub groups identified by a “strata” or characteristic they have in common. The sample proportion matches the sub group proportions.
Strength(s) of stratified sampling
It designed to make sure strata are not over’represented
Limitation(s) of stratified sampling
. Sometimes it is very difficult to sort certain people into an existing strata.
. Very time consuming
What is opportunity sampling?
Collecting a sample through asking whoever happens to be present at the time.
Strength(s) of opportunity sampling
.Very convient
Limitation(s) of opportunity sampling
. High researcher bias, as they’re the one choosing who to approach
. Because of the above reason, samples can be over-representative of a strata
What is volunteer sampling?
Advertising your study and waiting for people to volunteer for it.
Strength(s) of volunteer sampling
. Very convenient
. Might attract more compliant participants
Limitation(s) of volunteers sampling
. Could be very biased depending on the advertisement it could attract a very specific kind of character sometimes leading to unrepresentative samples
