Editing Snowball sampling (section)

===Peer Esteem Snowballing (PEST)===
Peer Esteem Snowballing is a variation of snowball sampling, useful for investigating small populations of expert opinion. Its proponents<ref name="Dimitrios">{{cite journal| author= Dimitrios C. Christopoulos |year=2010 |title= Peer Esteem Snowballing: A methodology for expert surveys}}</ref> argue that it has a number of advantages relative to other snowballing techniques:
# reduces the selection bias inherent in initial seed samples for a snowball by advocating for a nominations phase that objectively identifies contact seeds for the first wave; 
# by analysing network data it provides an estimate of the population size, unbiased by any researcher defined population boundary; 
# by reporting the estimate of the sample size vis a vis the population, it provides a measure of relative significance (optimal sampling data can be reported in this context); 
# through a network analysis of referrals it allows for identifying clusters of experts that may be instrumental in explain variations in their response profile; 
# allows for a referrals nominations strategy that, in certain cases, could improve response rates, while the nominations strategy acts as an ultimate validation of expertise for informants and therefore improves content validity.