The validity of abbreviated forms of the National Adult Reading Test and Spot-the-Word 2 for estimating full-scale IQ

Abstract

In this study, we validate an earlier proposal for an abridged 17-item National Adult Reading Test (NART) by comparing its performance in estimating full-scale IQ against both the full test and the Spot-the-Word 2 (STW-2) test in a new cohort. We also compare the performance of the 17-item NART to two previous attempts to shorten this test, the Mini-NART and the Short NART. Findings include that NART 17 is numerically stronger and statistically equivalent to the other short variants, the full 50-word NART, and STW-2. Unlike the Short NART, the 17-item NART is usable for participants of all ability levels rather than only those with low reading ability, while offering equally precise premorbid estimates. We also compute that two-thirds of STW-2 is ostensibly redundant for full-scale IQ estimation and we, therefore, propose that, subject to additional verification in an independent sample, an abridged version of this test may also benefit clinical practice.