1. A system, comprising: a memory containing a set of instructions; and a processor for processing the set of instructions, wherein the instruction cause the processor to perform a method comprising: receiving a current instance of search criteria; determining tokens in the current instance of the search criteria; for each document of at least one dataset, determining each token that has at least one occurrence thereof within the current instance of the search criteria and within the document; and for each document of the at least one dataset, generating a similarity score indicating a degree of relevance of contents of the document to the current instance of the search criteria, wherein generating a similarity score includes characterizing similarity based on a number of times each token present in both the document and the current instance of the search criteria and based on uniqueness of each token with respect to each other token.