Sampling techniques Flashcards
RANDOM SAMPLING
Every member of the target population has an equal chance of being selected
STRENGTHS OF RANDOM SAMPLING
It is unlikely that the samp,e will be biased as the sampler has no control over who is in the sample
All members of the target population have an equal chance of being chosen
WEAKNESSES OF RANDOM SAMPLING
It can take a long time, especially if the target population is large
OPPORTUNITY SAMPLE
The researcher just uses a group of participants that are readily available
STRENGTHS OF OPPORTUNITY SAMPLE
- The Mose convenient technique as it takes little preparation. You just use the first participants you can find. -So it takes less time to locate your sample than other techniques
It may be the only technique available because the whole target population cannot be listed
WEAKNESSES OF OPPORTUNITY SAMPLE
- it is inevitably biased because the sample is drawn from a special part of the target population which have unique characteristics and is not likely to be representative e.g shoppers at a mall ( likely to be unemployed)
-Participants may refuse to take part so the final sample also has the weakness of a volunteer sample e.g demand characteristics
SELF SELECT/ VOLUNTEER SAMPLING
Created when people respond to an advert for participants. They volunteer themselves for the research
STRENGTHS OF VOLUNTEER SAMPLE
- A convenient way to find willing participants
-participants less likely to drop out
-may be a good way to get a specialised group of participants- purposive sampling
WEAKNESS OF VOLUNTEER SAMPLE
(Volunteer bias)
Sample is biased because volunteers are likely to be more highly motivated & have extra time on their hands than the general population
- Volunteers may be more willing to be helpful and this may lead to to guessing the aims of the study and responding to demand characteristics
STRATIFIED SAMPLING
Proportional representation.
It reflects the target population by having the same proportions of key characteristics
E.g same % of male / female
STRENGTHS OF STRATIFIED SAMPLE
It can be very representative of the population
WEAKNESS OF STRATIFIED SAMPLE
It can be very time consuming to do and it also can be very difficult
Decision about which subgroups are used may be biased thus reducing the representation of the sample