Validation of a Model of Extramusical Influences on Solo and Small-Ensemble Festival Ratings

Abstract

This is the fourth in a series of studies whose purpose has been to develop a theoretical model of selected extramusical variables' ability to explain solo and small-ensemble festival ratings. Authors of the second and third of these (Bergee & McWhirter, 2005; Bergee & Westfall, 2005) used logistic regression as the basis for their model-building strategy. Modeling in these two studies strongly converged, demonstrating that performing as a soloist later in the day and entering from a large, metropolitan-area, relatively well-financed school were success indicators. The present study constitutes the validation phase of this series. First, the 2004 ratings data from a large Midwestern state's solo and small ensemble music festival were analyzed using binomial logistic regression. Model variables retained to this point in the process-time of day (morning/afternoon), geographical district (metropolitan/nonmetropolitan), district expenditure per average daily attendance (defined with two categorical variables), school size classification (highest/four lowest classifications), type of event (sololensemble), and the time of day by geographical district interaction—were regressed on a dichotomized ("I" vs. "not I" ) festival ratings variable. The model then underwent external (cross) validation by means of its application to the 2002 and 2003 festival data. Although some shrinkage was noted, results indicated an acceptable fit with these two data sets. For internal validation, 50 random samples of 25 % of the 2004 entrants were drawn and submitted to binomial logistic regression analysis. Then, 50 random samples of 10 % were drawn and likewise analyzed. Results indicated that estimated coefficients showed unbiasedness and consistency. On the other hand, a marked inefficiency among the estimates was found. The model also showed evidence of under specificity.