Code of Federal Regulations Title 23. Highways § 23.1340.8 Quality control

(a) Quality control monitors. Monitors shall conduct random, unannounced visits to no less than five percent of the observation sites for the purpose of quality control. The same individual shall not serve as both the observer and quality control monitor at the same observation site at the same time.

(b) Training. Observers and quality control monitors involved in seat belt use surveys shall have received training in data collection procedures within the past twelve months. Observers and quality control monitors shall be trained in the observation procedures of § 1340.7 and in the substitution and rescheduling requirements of § 1340.5(c).

(c) Statistical review. Survey results shall be reviewed and approved by a survey statistician, i.e., a person with knowledge of the design of probability-based multi-stage samples, statistical estimators from such designs, and variance estimation of such estimators.