SIMPLIFYING THE IMPLICATION-REALIZATION MODEL OF MELODIC EXPECTANCY

Results from previous investigations indicate that the implication-rea lization (I-R) model (Narmour, 1990) of expectancy in melody may be ov erspecified and more complex than necessary. Indeed, Schellenberg's (1 996) revised model, with two fewer predictor variables, improved predi ctive accuracy compared with the original model. A reanalysis of data reported by Cuddy and Lunney (1995) provided similar results. When the principles of the I-R model were submitted to a principal-components analysis, a solution containing three orthogonal (uncorrelated) factor s retained the accuracy of the model but was inferior to the revised m odel. A separate principal-components analysis of the predictors of th e revised model yielded a two-factor solution that did not compromise the revised model's predictive power. Consequently, an even simpler mo del of melodic expectancy was derived. These results provide further e vidence that redundancy in the I-R model can be eliminated without los s of predictive accuracy.