Abstract: Systems are described in the field of machine learning such as natural language processing for use in researching and searching a corpus of documents in various topical areas such as physical and social sciences. The systems may utilize training, testing, and deployment of models representing a defined space within the corpus. A network of computers and user input devices may be used for receiving research queries via human-computer interface devices and application programming interfaces. Queries may be processed and used as input to the machine learning models. Outputs from the models may include ranking of results reflecting the queries.