Descriptional complexity has historically been a multidisciplinary area of study, with contributions from automata theory, computational complexity, cryptography, information theory, probability, statistics, pattern recognition, machine learning, computational learning theory, computer vision, neural networks, formal languages and other fields. Some basic questions are: How succinctly can a descriptional system represent objects (for example, encoded as formal languages) in comparison with other descriptional systems? What is the maximal size trade-off when changing from one system to another, and can it be achieved?