Sample group of people used for research purposes who have been selected at the discretion of the interviewer. The interviewer will be instructed to make selections from a minimum number of persons who fulfill the researcher's quota classifications. Classifications are usually based on census data and will correspond to the composition of the area under study. However, the field visits and choices are the responsibility of the interviewer, and often conditions will occur so that the sample will not be a true representation. For example: An interviewer may not choose people who live on high floors in non-elevator buildings because the interviewer may not want to walk up so many stairs. Consequently, the results of the research may not represent the actual picture, even though the researcher's quotas for each classification may have been filled.
