Test-retest reliability and practice effects of Expanded Halstead-Reitan neuropsychological test battery

Test-retest reliabilities and practice effects of a broad range of neuropsy chological measures were examined in 384 normal or neurologically stable ad ults. Median test-retest interval was 11 months (range 3-16 months). The re liability estimates for most of the measures are reasonably good, ranging f rom .70 to low .90s. en exception is the relatively poor reliabilities of m ost memory measures. For all test measures, the value on initial testing is a strong determinant of the value on the second examination. Practice effe cts are seen on most measures. The magnitude of the practice effects, howev er, varies as a function of type of measure, test-retest interval, age, and overall competency level, of the participant. This study provides several types of retest information that may be useful for future research and clin ical work: comparative reliabilities of the various measures, estimate of e rror variability associated with each administration, standard deviation of the change, and comparative magnitude of practice effects on various tests .