Randomness means different things in various fields. Commonly, it means lack of pattern or predictability in events. The Oxford English Dictionary defines “random” as “Having no definite aim or purpose; not sent or guided in a particular direction; made, done, occurring, etc. , without method or conscious choice; haphazard. ” This concept of randomness suggests a non-order or non-coherence in a sequence of symbols or steps, such that there is no intelligible pattern or combination.