Reliability and validity
To evaluate the examiner’s (i.e., school nurses) reliability in carrying out dental examinations, three school nurses and twenty pupils from their schools were randomly selected. The dental examinations were carried out on all twenty pupils by each of these school nurses. The Fleiss' kappa (19), for evaluating agreements between three school nurses for caries severity, was found to be 0.87, indicating a high level of agreement between them. In addition, to assure the validity of the nurses’ findings, a dentist conducted dental examinations on the same twenty pupils. Then the results were compared with those of school nurses. Cohen's kappa (
(19), between the dentist and each school nurse was high (
=0.89 for examiner 1,
=0.90 for examiner 2 and
=0.81 for ex-aminer 3), indicating that the results of examina-tions by school nurses were valid.