Stylistic Changes for Temporal Text Classification

This paper investigates stylistic changes in a set of Portuguese historical texts ranging from the 17 to the early 20 century and presents a supervised method to classify them per century. Four stylistic features – average sentence length (ASL), average word length (AWL), lexical density (LD), and lexical richness (LR) – were automatically extracted for each sub-corpus. The initial analysis of diachronic changes in these four features revealed that the texts written in the 17 and 18 centuries have similar AWL, LD and LR, which differ significantly from those in the texts written in the 19 and 20 centuries. This information was later used in automatic classification of texts per century, leading to an F-Measure of 0.92.