1. A method of automatically generating a lemma dictionary from a web resource, the method comprising: extracting a plurality of tokens from text-based documents within the web resource; generating a plurality of N-grams from the plurality of tokens; receiving one or more filter definitions that identify valid N-grams; filtering the plurality of N-grams using the one or more filter definitions to generate a lemma dictionary; generating an ontology that comprises the lemma dictionary; causing a user interface to display a network of nodes representing the lemma dictionary; and receiving one or more inputs that assign ontology relationships to the network of nodes.