Danger: High Power! – Exploring the Statistical Properties of a Test for Random Forest Variable Importance

Random forests have become a widely-used predictive model in many scientific disciplines within the past few years. Additionally, they are increasingly popular for assessing variable importance, e.g., in genetics and bioinformatics. We highlight both advantages and limitations of different variable importance scores and associated testing procedures, especially in the context of correlated predictor variables. For the test of Breiman and Cutler (2008), we investigate the statistical properties and find that the power of the test depends both on the sample size and the number of trees, an arbitrarily chosen tuning parameter, leading to undesired results that nullify any significance judgments. Moreover, the specification of the null hypothesis of this test is discussed in the context of correlated predictor variables

SameSameButDifferent v.02 – Iceland

The history of computer music is to a great extent the history of algorithmic composition. Here generative approaches are seen as an artistic technique. However, the generation of algorithmic music is normally done in the studio, where the music is aesthetically valued by the composer. The public only gets to know one, or perhaps few, variations of the expressive scope of the algorithmic system itself. In this paper, we describe a generative music system of infinite compositions, where the system itself is aimed for distribution and to be used on personal computers. This system has a dual structure of a compositional score and a performer that performs the score in real-time every time a piece is played. We trace the contextual background of such systems and potential future applications