Once preliminary interviewing has been evaluated, the project manager will prepare additional interviewers for the project if they are needed. Specific procedures are followed to maintain internal control, which is of primary importance for proper project execution. Reviewing specific study objectives with all interviewers is essential.

• Briefing interviewers who have been trained for a particular project is just the first part of conducting a study.
• Follow-up briefings and project adjustments are conducted on a daily basis throughout the length of the study.
• A taped version of these "how-to" sessions is kept in the office for interviewers to review if clarification is desired.
• Before any interviewer begins a project, mock interviews are conducted with the project manager. Subjects are contacted by the interviewer only after satisfactory performance is obtained.
• The project manager monitors interviews with listen-in technology over the entire course of the study, adjusting the interviewer's approach and style as necessary.