Protocols from 108 administrations of the Reynolds Intellectual Assessment Scales were evaluated to determine the frequency of examiner errors and their impact on the accuracy of three test composite scores, the Composite Ability Index (CIX), Verbal Ability Index (VIX), and Nonverbal Ability Index (NIX). Students committed at least one administration, scoring, or recording error on 98% of protocols and averaged 7.53 errors per protocol. Administration errors were most common on VIX subtests (Guess What and Verbal Reasoning), whereas recording errors occurred most frequently on NIX subtests (Odd Item Out and What's Missing). Error correction and rescoring resulted in changes to all three index scores, although VIX and CIX changed most frequently.