The methods of interviewer selection in current use are examined, reference being made to those described by Dr. Noelle Neumann and Mr. Paul Berent in their papers read at the Esomar Congress in Evian in 1962. The interviewer selection methods used by InterScan are examined and experimental work to test the validity of the procedure is discussed and the conclusions stated. Interviewer training methods in current use are reviewed, and a method which has proved effective is discussed. Variations in interviewing techniques used in different companies and described in the U.K. Market Research Society's publication "Fieldwork Methods in General Use" (Dec. 1968) are examined and solutions to some of the problems raised are suggested. Various methods of field control and supervision are described. Quality control is discussed and methods of avoiding and detecting interviewer dishonesty are given.