37. The system of claim 20 , the operations comprising: clustering the relationship graph; and sending a computing device from which the selected topic is received instructions to display a graphical representation of the clustered relationship graph.
20. A system, comprising: one or more processors; and memory storing instructions that when executed by at least some of the processors effectuate operations comprising: obtaining a corpus of more than 500 documents, each document having unstructured natural language text; obtaining a set of topics and, for each topic in the set, a respective set of n-grams pertaining to the respective topic; receiving a selected topic among the set of topics, the selection indicating that relationships between the documents are to be enhanced or suppressed in virtue of the relationships arising from text relating to the selected topic; forming a relationship graph of the documents, the relationship graph having more than 500 nodes, each node corresponding to at least one document, the graph having edges between nodes indicating a relationship between documents corresponding to the respective nodes, wherein: forming the relationship graph comprises forming a feature vector for each document, each feature vector having plurality of scores, each score corresponding to a given n-gram and being based on: an amount of occurrences of the given n-gram in the respective document, a length of the respective document, an amount of occurrences of the given n-gram in a plurality of other documents different from the respective document, and whether the given n-gram is among the set of n-grams pertaining to the selected topic and, when the given n-gram pertains to the selected topic, a cardinal score indicating an amount that the given n-gram pertains to the selected topic, the relationships between pairs of the documents are determined based on co-occurrence of n-grams in the pairs of the documents, and wherein the relationships are enhanced or suppressed in response to co-occurring n-grams being in the respective set of n-grams of the selected topic; and storing the relationship graph in memory.