Types of sampling Flashcards
(15 cards)
What is random sampling?
This method gives every member of the target group an equal chance of being selected for the sample eg. By assigning a number to each member, and then selecting from the pool by using a random number generator
What is a strength of random sampling?
Bias free, no subjectivity
What is a weakness of random sampling?
Doesn’t guarantee a representative sample, small minority groups may distort results
What is systematic sampling?
Involves a sample being obtained by selecting every nth person
What is a strength of systematic sampling?
Bias free as participants are selected using an objective system
What is a weakness of systematic sampling?
Not truly random unless one selects a number using a random method and starts with this person and selects every nth person
What is opportunity sampling?
Involves a sample of participants produced by selecting people who are most easily available at the time of study
What is a strength of opportunity sampling?
Quick strategy, easy to carry out
What is a weakness of opportunity sampling?
Participants likely to be of a similar demographic, meaning the sample will be unrepresentative of the entire population
What is volunteer sampling?
Involves a sample of participants that relies solely on volunteers to make up the sample
What is a strength of volunteer sampling?
Often achieves a large sample size through reaching a wide audience, for example with online advertisements
What is a weakness of volunteer sampling?
Participants are likely to be motivated / have an interest and therefore may work out the aim of the study and/or show demand characteristics
What is stratified sampling?
Involves a sample of participants produced by identifying subgroups according to their frequency in the population, and then participants are selected randomly from the subgroups
What is a strength of stratified sampling?
Likely to be more representative than any other methods because there is a proportional and randomly selected representation of subgroups
What is a weakness of stratified sampling?
Very time consuming to identify subgroups, then randomly select participants and contact them
