Evolution in Hollywood editing patterns?

Cutting, Delong and Nothelfer (2010) use statistical methods to investigate the evolution of shot-length patterns in popular film. They argue, using what they call a ‘modified autoregressive index’ (mAR), that patterns are becoming increasingly clustered and also evolving towards 1/f structure, a pattern described in later publication as ‘like those that our minds may naturally generate’. This paper shows that the interpretation of the mAR index is wrong. It is also shown that that the results concerning 1/f patterns can be interpreted in an equally plausible and much less ‘exciting’ way. That is, although there are undoubtedly interesting temporal patterns in the shot length structure, they can’t be interpreted in terms of the ‘evolution of Hollywood film’ in the sense intended in the original paper.