The psychometric properties of the English language version of the Aachen Aphasia Test (EAAT)

This article reports results of a standardization study of the English lang uage version of the Aachen aphasia test (EAAT). The EAAT was administered t o 135 speakers with and 93 without aphasia. Aphasic speakers were divided i nto four groups (n = 30) representing EAAT standard syndrome groups (global , amnestic, Broca's and Wernicke's aphasia), and 15 speakers who could not be classified into the standard groups. Without aphasia were 24 nonhospital ized and 41 hospitalized speakers with no history of neurological illness o r speech-language disorder and 28 speakers with a history of neurological i llness, but no aphasia. Hierarchical cluster analysis (complete linkage) de monstrated the validity of the linguistically motivated construction of the EATT. This was further confirmed for the main subtests through nonmetric m ultidimensional scaling (smallest space analysis). The property of increasi ng complexity across subparts of subtests was also confirmed. Nonparametric discriminant analyses showed the high differential validity of the EAAT fo r distinguishing between aphasia-no aphasia and acceptably high validity fo r separating out subgroups of speakers. Consistency coefficients (Cronbach' s alpha) illustrate the high to very high internal consistency of the subte sts. We argue for the applicability to the EAAT of the original German reli ability studies which showed retest and inter- and intra-rater reliability to be high. We conclude that the EAAT amply meets criterion levels for a ps ychometrically robust test.