The SFI emphasis on the importance of information in the study of complex structure is based on a long tradition in theoretical physics. Since that time, though, it has become better appreciated that measuring the randomness and unpredict ability of a system does not completely capture the correctional structure in its behavior.
Structure here is taken to be a statement about the relationship between a system'scomponents.
Structure and correlation are not completely independent of randomness, however. It is generally agreed that both maximally random and perfectly ordered systems possess no structure. Nevertheless, at a given level of randomness away from these extremes, there can be an enormously wide range of differently structured processes. These realizations led to a considerable effort to develop a general measure that quantifies the degree of structure or pattern present in a process. There are many ad hoc methods for detecting structure, but none is as widely applicable as entropy is for indicating randomness.