Published online by Cambridge University Press: 28 November 2008
In reconstructing protoforms and linguistic histories, many methods can and have been employed with varying degrees of effectiveness (cf. Bonfante, 1945, for a general discussion). For the specific purpose of establishing the time sequence of phonological changes according to which sound systems have evolved, traditionally two procedures have been most frequently followed: one is to sift the historical records for clues to the dates of linguistic innovations, and the other is to infer from the systematic correspondences between protoforms and their modern reflexes the internally motivated order of diachronic rules.