COMPLEXITY AS UNPREDICTABILITY OF THE SCALING DYNAMICS

The problem of quantifying complexity is discussed in the framework of a hierarchical modelling of physical systems. The dynamics underlying the formation of onedimensional symbolic patterns is unfolded by using variable-length prefix-free codewords and described by means of allowed transitions on a <logic>t>r ee. The derived model is employed to make predictions on the scaling behaviour of the system's observables at each level of resolution. The complexity of the system, relative to the unfolding scheme, is evaluated through a generalization of the information gain by comparing prediction and observation. © 1990 IOP Publishing Ltd.