Skip to main content

Table 6 Different types of sampling methods and ways of using them

From: Purposive sampling in a qualitative evidence synthesis: a worked example from a synthesis on parental perceptions of vaccination communication

Type of sampling [14] Used or not used in this sampling framework Potential ways in which we could use it in future
Extreme or deviant case sampling We did not use this type of sampling in this review This approach could be very useful when setting out sampling for a review when the review question addresses why something did or did not work or when re sampling after you have a set of findings i.e. when updating a review
Maximum variation sampling Used to help create our sampling frame We used this to create the first step of our sampling frame. It could also be useful to apply when sampling for other variables such as intervention, population or socioeconomic status.
Snowball or chain sampling We did not use this type of sampling in this review We believe that this approach could be used if there were key articles in the field. However, it should still be supported by a systematic search and sampling.
Theoretical or operational construct sampling We did not use this type of sampling in this review Useful if performing a systematic review of different theoretical or operational constructs. For example, theories of behaviour change as applied to different smoking prevention programs.
Criterion sampling Used to help create our sampling frame We decided on the criterion that were central to our research objective and created a sampling framework around them.
Stratified purposeful sampling We did not use this type of sampling in this review We have since used this approach in another review where we divided the studies by population and then applied the same sampling frame to each population.
Purposeful random sampling We did not use this type of sampling in this review We do not regard random sampling as useful or appropriate when trying to explore a specific phenomenon of interest
Combination or mixed purposeful sampling Used to help create our sampling frame We combined different sampling methods to create our three step sampling frame that worked for our specific research objective