COMMENT: ON RESPONDENT-DRIVEN SAMPLING AND SNOWBALL SAMPLING IN HARD-TO-REACH POPULATIONS AND SNOWBALL SAMPLING NOT IN HARD-TO-REACH POPULATIONS

Coleman (1958-1959) notes that snowball sampling in survey research is amenable to the same scientific procedures as ordinary random sampling, and Goodman (1961) introduces statistical methods with snowball sampling for the estimation of various given relationships among the people in a given population of interest (not in a hard-to-reach population) - methods that were designed specifically for the purpose of estimating statistically social structure in this population of interest. Snowball sampling is described in Goodman (1961) as a method of sampling that makes possible, for example, the statistical estimation of the number of mutual relations in a given population - the statistical estimation of the number of pairs of individuals in a population who would name each other (as, for example, "best friend," or "the person with whom he/she most frequently associates," or "the person whose opinion he/she most frequently seeks").