Quota sampling

A nonprobability sampling technique chosen in such a way that the proportion of sample elements possessing a certain characteristic is approximately the same as the proportion of the elements with the characteristic in the population; each field worker is assigned a quota which specifies the characteristics of the people he is to contact. In other words, the quotas ensure that the composition of the sample is the same as the composition of the population with respect to the characteristics of interest. Once the quotas have been assigned, there is considerable freedom in selecting the elements to be included in the sample.