Thematic part: Language change (Preface)

Theories of language change have been the subject of linguistic debates for centuries. It is therefore once again important to discuss such theories and models from a qualitative as well as a quantitative point of view. For this reason, Glottotheory, as a magazine for the dialog between qualitative and quantitative linguistics, presents a thematic part on language change. Five contributions of different provenance are presented. The so-called Piotrowsky law is one of themost prominentmodels of linguistic change. Against this background, Kamil Stachowski (Cracow, Poland) discusses in Piotrowski-Altmann law. State of the art the history of the law, its several variants and applications, and some theoretical problems connected with it. Stachowsky concludes that the Piotrowsky law is in fact a group of psychological and sociological models. Under the title Language change and language evolution: Cousins, siblings, twins? Stefan Hartmann (Bamberg, Germany) argues that the partially synonymous use of the terms language change and language evolution can be explained by parallel developments both in historical linguistics and in the field of language evolution research. The article by Hartmann critically combines two approaches in particular (complex adaptive systems and construction grammar) into one integrated approach that seek to explain both language emergence and language change over historical time. Language change as a scientific construct of a probabilistically organized information system is the subject of the contribution of Eike U. Decker (Heidelberg, Germany). He discusses language change from an information and systems theoretical point of view. It is argued that human language must be regarded as a probabilistically organized information system in which synchronizations of the linguistic systems of individuals create unstable collective levels. Following Decker’s model, probabilistic organization of language processing on an individual level leads to probabilistic organization of language systems as a whole. Therefore, language change in its “classical sense” (a change in linguistic objects) must be reinterpreted as a change in probability distribution. In conclusion,