Every interviewer receives a personal briefing before each study capitalised on extensive ongoing training
. Pre-test to 'evaluate' the interviewer
. Equip all interviewers with an interviewer manual
. Interviewer hotline is provided for interviewers at all times for queries
. Intensive briefing of interviewers by project manager (and customer) before each project.
. Independent monitoring department
. Quality control of surveys by specially trained moderators for completeness, handling of the survey materials, technical accuracy and plausibility.
. Quota monitoring by the project manager
. Monitoring of the interviewers: Telephone and written monitoring of a randomly selected group of people surveyed (usually 30% of the overall control sample).