Assessing frequency changes in multistage diachronic corpora: Applications for historical corpus linguistics and the study of language acquisition

The use of corpora that are divided into temporally ordered stages is becoming increasingly wide-spread in historical corpus linguistics. This development is partly due to the fact that more and more resources of this kind are being developed. Since the assessment of frequency changes over multiple periods of time is a relatively recent practice, there are few agreed-upon standards of how such trends should be statistically interpreted. This article addresses the need for a basic analytical toolbox that is specifically tailored to the interpretation of frequency changes in multistage diachronic corpora. We present a number of suggestions for the analysis of data that analysts commonly face in historical studies, but also in the study of language acquisition.