The authors begin by describing some challenges to psychological inquiry and to the understanding of simultaneous interpretation. The authors then articulate the computational and hypothesis-testing approach to inquiry, and illustrate a general information-processing model. The authors discuss some experimental and theoretical studies of language processing carried out within the information-processing approach. The authors analyse not only behavioural measures of language processing but also its phenomenal experience. The authors close with a review of two current hypotheses about simultaneous interpretation and consider some methodological hurdles in the study of this fascinating skill.