 Among the things to note about this work is that it was all done on directly recorded performance data: transcripts of people speaking to each other spontaneously on the phone in the case of the Switchboard corpus, stories as written by newspaper journalists in the case of WSJ, measured responses of volunteer subjects in a laboratory in the case of the psycholinguistic experiments of Bresnan and Ford (2010). The focus is on identifying the factors in linguistic performance that permit accurate prediction of future performance, and the methods of investigation have a replicability and checkability that is familiar in the natural sciences.