1. A method of determining a relevancy ranking score, comprising: receiving a query including one or more constraints, wherein one of the one or more constraints includes an operator, wherein the operator comprises one or more of the following: CONTAINS, DOES_NOT_CONTAIN, BEGINS_WITH, ENDS_WITH, ALWAYS_WITHIN, AND, OR, NOT, EQUALS, NOT_EQUALS, GREATER_THAN, LESS_THAN, GREATER_THAN_OR_EQUAL_TO, LESS_THAN_OR_EQUAL_TO; receiving a search result based on the query; and determining, using a processor, the relevancy ranking score for the received search result based at least in part on the operator associated with the one or more constraints of the query, wherein the relevancy ranking score comprises a sum of three or more feature scores each multiplied by a separate weight, wherein the three or more feature scores comprise a scope or depth score, an accuracy or validity score, a clarity score, a currency score, or a source score, and wherein the scope or depth score comprises a score indicating satisfied constraints, and wherein the accuracy or validity score comprises a score indicating constraints improving query precision, and wherein the clarity score comprises a score indicating information presented in a clear manner, and wherein the currency score comprises a score indicating more recent results, and wherein the source score comprises a score indicating source quality, wherein presented in the clear manner for the clarity score comprises having a higher score in an event in which a title, an abstract, or a date is present.