1. A system including instructions recorded on a non-transitory computer-readable medium, and executable by at least one processor, the system comprising: an event type generator configured to cause the at least one processor to provide a training set for training a supervised machine learning algorithm to classify documents with respect to an event type, the event type generator including a request handler configured to receive the event type and at least one example document designated as being associated with the event type; a text analyzer configured to extract first entities from the at least one example document; and a result manager configured to execute a first search against an indexed corpus of documents, using the first entities, to obtain first search results, and further configured to receive at least one selected document from the first search results, wherein the request handler is further configured to extract second entities from the at least one selected document, and execute a second search against the indexed corpus of documents, using the second entities, to obtain second search results, and wherein the event type generator is further configured to provide the at least one example document, the first search results, and the second search results as the training set.