Abstract
The Spanish version of the WAIS-III scale was published two year after the American one only. Taking into account the polemic about the factor structure of the previous versions (WAIS, and WAIS-R), it is critical to test what this new scale is assessing. Several structural models were analysed in the total sample (N = 1369), and in every normative age group through confirmatory factor analysis procedures. A model with four first-order factors (Verbal, Perceptual Organisation, Working Memory and Processing Speed) presents the best fit in all samples. When a second-order factor (identified with the g factor) is added to this model, the fit indexes also show acceptable values. Results support that g would be the main cognitive ability assessed by the WAIS-III. Implications for the scores computed after the scale (Total IQ, Verbal IQ, Performance IQ, and four cognitive indexes) are discussed.
