• Article

Controlled sampling for comparing two populations - An example

When the objective of a study is to compare with respect to one

variable two populations that are inherently different along related

dimensions, a standard probability sample is not always appropriate

since there is no control over extraneous variables that may be

related to the key indicators of interest. This paper discusses a

sample designed to study the effect of ethnicity on drinking behavior by

comparing Irish and Puerto Ricans in New York City. A random sample of

both populations would have almost certainly produced an Irish sample

with a higher average socioeconomic level than the Puerto Rican sample.

Furthermore, since the total sample size was only 1,000, limiting the

analysis to the comparable subpopulations would have resulted in

unacceptably small effective sample sizes. Controlled sampling was used

to favor selection of areas which according to census data contained

members of each ethnic group of similar socioeconomic background I .

The paper concentrates on the preparation of the sample frame which

is the innovative aspect of this design.


Krotki, K., & Porcellini, L. (1990). Controlled sampling for comparing two populations - An example. Proceedings of the Survey Research Methods Section (ASA), 683-687.