The applicability of the Kaufman Assessment Battery for Children (K-ABC) with older adults (50+ years) with moderate, severe and profound intellectual impairment.

To define the intellectual characteristics of a population of older people (50+ years) with severe intellectual impairment who were the focus of a wider demographic study, participants were assessed on the Kaufman Assessment Battery for Children (K-ABC). Test material was modified to make it age-appropriate and culturally suitable. Of the 122 people in the population [chronological age (CA) = 63.5 years; range 50-90 years], 61 were successfully tested on the K-ABC (CA = 60.9 years; range 51-81 years). Factor analysis closely replicated the factorial structure demonstrated for younger children. Separate Sequential and Simultaneous Mental Processing factors were identified, with subtests from the Achievement Scale loading on these factors and not constituting a separate factor. Application of hierarchical cluster analysis confirmed the factor structures. Inferences in relation to cognitive development from a Piagetian perspective are drawn, and the utility of information on mental processing for educational intervention with older persons with severe intellectual impairment is noted.