1. A method comprising: receiving, by a computing device, a search category and a current query from a current user; determining, by the computing device, relevance of documents comprising a corpus of documents relating to the search category; obtaining, by the computing device, degree of interest data by users in one or more documents of the corpus of documents, the degree of interest data determined by a degree of interest data group including one or more of measuring how fast a user reads the one or more documents based on page scroll speed and average reading time based on length of the one or more documents, whether the user chose to cut and paste a portion of the document for further reading, whether the user bookmarked the one or more documents, or combinations thereof; determining, by the computing device, documents comprising a search result and an order of the documents comprising the search result based on the determined relevance and obtained degree of interest data; obtaining, by the computing device, direct search query terms from the users; identifying, by the computing device, document query terms from content of the corpus of documents; determining, by the computing device, query to query correlations from a query correlation data structure, where the determining of the query to query correlations comprises tracking query terms provided by the users in past search sessions which the users selected and where the query correlation data structure comprises, for each pair of the query terms, a measure selected from a group of measures consisting of a probability of co-occurrence in past user sessions and a degree of co-occurrence in a document of the corpus of documents; determining, by the computing device, at least one query suggestion, the at least one query suggestion obtained from the direct search query terms, document query terms, and the query to query correlations; tracking, by the computing device, (a) the search category and the current query specified by the current user, (b) interaction with each document clicked through from the documents comprising the search result, and (c) a query selected from the at least one query suggestion, to develop session history for both the users in the past search sessions and the current user; and generating, by the computing device, a search results web page from the interaction with the each document and the documents comprising the search result, ordered in the determined order, the search result web page comprising the at least one query suggestion.