Functional equivalence of the National Adult Reading Test (NART) and Schonell reading tests and NART norms in the Dynamic Analyses to Optimise Ageing (DYNOPTA) project
This study investigates the functional equivalence of two measures of irregular word pronunciation—National Adult Reading Test (NART) and Schonell—which are popular instruments used to assess verbal neurocognitive functioning and to estimate premorbid IQ. We report norms for the NART in a pooled sample from 3 Australian population-based studies of adults aged 65-103 years. Norms were stratified by sex and age left school in 5-year age groups. The NART and the Schonell had a strong linear relation, allowing for the imputation of NART scores based on Schonell performance within 1 study. Neither measure was sensitive to the effects of sex after adjusting for the effects of age and education. Early school leavers performed worse on both measures. Data pooling enables greater precision and improved generalizability of NART norms than do methods that use single older adult samples.
We describe the development of a 35-item, oral word-reading test with two equivalent forms (HART-A and HART-B) designed to estimate premorbid abilities. Both forms show excellent internal consistency (coefficients alpha >.91) and test-retest reliability (Pearson rs >.90). HART performance was combined with demographic variables to generate regression equations that predict IQ scores obtained concurrently and 4-8 years earlier. The resulting models explained 61% of full scale IQ (FSIQ) variability in 327 healthy adults. The FSIQs that can be estimated range from below 73 to above 131. Combined with demographic variables, these two brief word reading tests accurately predict a broader range of IQs than Blair and Spreen’s (1989) longer version. Equivalent forms make it especially useful for longitudinal studies.