This book presents the use of kernel smoothing , a family of methods adapted from fields such as signal processing, as a way to identify the true spatial distribution of linguistic forms at particular points in time.  Discusses the use of kernel smoothing in historical dialectology and new approaches to parameter setting Presents a series of case studies from the history of Norwegian language Investigates some of the major phonological and morphosyntactic shifts which transformed the language from Old Norwegian through Middle to early Modern Norwegian Demonstrates how the kernel smoothing method allows us to see how these changes spread from place to place, and these findings are used to throw light on a number of more general research questions of interest to an audience beyond Scandinavianists A step-by-step guide to kernel smoothing is offered, so that non-experts can apply the approach to their own data