wvenable@spam.ua.oz (Bill Venables) (07/20/90)
In article <5533@uceng.UC.EDU> ddahmer@uceng.UC.EDU (Hello World!) writes: >... I am posting this again as I need a larger number of responses to >go by for statistical purposes. (At least 30 in a sample to model a >population, etc.) ... I feel obliged to sound a warning of the dangers of drawing inferences from self-selected rather than random samples. Sample size by itself is no safeguard against wildy erroneous conclusions. -- Bill Venables, Dept. Statistics, | Email: wvenable@spam.ua.oz.au Univ. of Adelaide, South Australia. | Phone: +61 8 228 5412
dgoudge@nmsu.edu (Darrell Goudge) (07/28/90)
In article <345@spam.ua.oz> wvenable@spam.ua.oz (Bill Venables) writes: >In article <5533@uceng.UC.EDU> ddahmer@uceng.UC.EDU (Hello World!) writes: >>... I am posting this again as I need a larger number of responses to >>go by for statistical purposes. (At least 30 in a sample to model a >>population, etc.) ... > >I feel obliged to sound a warning of the dangers of drawing inferences >from self-selected rather than random samples. Sample size by itself >is no safeguard against wildy erroneous conclusions. > >-- I think the caution of using a convenience sample especially collection for the express purpose of increasing power is well founded, unless the sampling frame is the population of interest. In this case the population of interest could be the individuals who read this group and wish to participate in this survey. Darrell Goudge Marketing Department New Mexico State University Las Cruces, New Mexico 88003