14. The non-transitory, computer-readable medium of claim 10 wherein the one or more filter definitions comprises a minimum frequency for an N-gram to appear in the web resource.
10. A non-transitory, computer-readable medium comprising instructions which, when executed by one or more processors, causes the one or more processors to perform operations 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.