20th
Snowballing sampling technique
Source http://cyberron.blogspot.com/2009/07/snowballing-sampling-technique.html
“Establishing the sample and the sampling process in qualitative inquiry is almost often a subject of contention, and takes much more time in persuading panel members during research defense sessions. A systematic sampling process in qualitative research designs is rarely established. Often, what is used is a very arbitrary and uninformed purposive sampling technique (sample identified on purpose).
The snowballing sampling technique is a systematic non-probabilistic purposive sampling method that is very apt for qualitative research. Highly qualitative and exploratory studies call for a purposive non-probability sampling design, which is not after the representativeness of samples. A purposive non-probability sampling design relies heavily on the availability of respondents, especially those who are difficult to locate for interviews.
A snowballing sampling technique can be employed to seek out informants or respondents, who are otherwise difficult to locate and identify. The snowballing sampling method is akin to the opportunity sampling technique, the chaining sampling technique and the referral sampling technique (referred informants).
The snowballing sampling technique is most proper when the members of the target respondents are difficult to locate. A snowball is the process of accumulation of referrals as each located and interviewed informant suggests other informants whom they happen to know and locate. For Arce, it “results from one key informant being interviewed and asked for suggestions on who else might be good informants, and the next informant is chosen on the basis of this suggestion.” As an opportunity sampling technique, the informants were selected and interviewed mainly because they were located and made available for and in a particular study. David used accidental non-probability sampling technique as a derivative of the opportunity sampling technique. In accidental sampling technique, the respondents were chosen as they become available. This technique resembled that of Garson’s chain sampling method, where the aim is to “obtain a saturation of informants….to reveal common cultural understanding….in a chaining process.”
References:
Babbie, Earl. 1998. The Practice of Social Research (8th ed). Wadsworth: Thomson Learning Inc.
David, Fely P. 2002. Understanding and Doing Research: A Handbook for Beginners. Iloilo City: Central Philippine University – Social Science Research Institute.
