Adopting a psycholinguistic approach to professional SI, Chernov defines it as a task performed in a single pass concurrently with the source language speech, under extreme perception and production conditions in which only a limited amount of information can be processed at any given time. Being both a researcher and a practitioner, Chernov drew from a rich interpreting corpus to create the first comprehensive model of simultaneous interpretation. His model draws on semantics, pragmatics, Russian Activity Theory and the SI communicative situation to formulate the principles of objective and subjective redundancy and identify probability prediction as the enabling mechanism of SI.