A computer implemented information retrieval system is provided. The system includes a user input configured to receive a user query relative to the corpus. A machine learning classifier is trained with a first set of training data comprising anchor text relative to at least some of the documents in the corpus. A processing unit is adapted to interact with the classifier to obtain search results relative to the query using the machine learning classifier. In some aspects, the classifier is also trained with a second set of training data. A method of integrating a new document into a corpus of documents is also provided. A method of training a machine learning classifier for retrieving documents from a corpus using two distinct types of training data is also provided.