The Attention Network Test (ANT) measures the efficacy of the alerting, orienting, and executive networks. Ten sessions of the ANT (Fan et al., Callejas et al., or Rueda et al.) were administered to younger children, younger adults, and older adults. Participants indicated the direction of a target (e.g., arrow), accompanied by congruent or incongruent distractors. The targets were preceded by visual or auditory cues. Despite some practice effects, all network scores remained highly significant even after nine previous sessions. The relatively poor reliability of network scores with one session of data rises to respectable levels as more data is added.