Mining the Differences between Penninc and Vostaert

The Middle Dutch Roman van Walewein (Romance of Gauvain, ca. 1260) was written by two authors, Penninc and Vostaert. Only one manuscript containing the complete text, explicitly dated as copied in the year 1350, is left to us. Some fragments of another, probably somewhat younger manuscript contain about 400 lines. The text in the complete manuscript consists of 11,202 lines of rhyming verse. The manuscript was written by two clerks. The first seems to have written the lines 1-5.781 and the second the lines 5,782-11,202.

The second author, Vostaert, explicitly claims to have added about 3,300 lines to Penninc's text. Because scholars of Middle Dutch literature came up with other amounts, we decided to try out modern authorship attribution techniques to find out whether these would point to a specific line in the text where the text before and the text after contrasts most. We used a lexical richness measure, Udney Yule's Characteristic K, and Burrows's Delta, measuring the differences of frequencies of the most frequent words in different parts of the text. We split the text into largely overlapping parts of 2000 lines, moving through the text in order to search for an exact line in the text where the contrast before and after would be the most significant. For measuring Burrows's Delta this meant that for the sake of our focus on one text (or two, in a way), we considered the text as a ‘group of texts' and every ‘part' of 2000 lines as a separate text, to be compared with the other 'texts'.

At the conference in Gothenburg in 2004 we were able to show that both measures yielded the lines 7,881-2 as the point of the most contrast. In Fig. 1 we present the results of Yule's K for that part of the text and in Fig. 2 the results of our creative use of Burrows's Delta can be found. It is very intriguing that both measurements point to the same place in the text. This suggests that line 7,882 could very well be the place where Vostaert took over from Penninc.

We continue our research by concentrating on a quantitative analysis of the differences between the two parts of the text. What are in fact the lexical differences between the text parts before and after line 7,881-2? To find out, we made a list of lemmata (headwords, comprising all spelling variants or inflections etc. of a word) that occur significantly more in the lines before and in the lines after. The top of this list looks as follows:

[etc.]

Summarizing, Penninc makes significantly more use of the first and second person of the personal pronoun, in contrast to a significantly higher use of the third person by Vostaert. Penninc also applies a lot more modal verbs. But why? Are there several reasons for these differences, or can all be explained by only one or two ‘special effects' of the individual authors?

The first hypothesis we will explore is that a difference in the amount of dialogue between the two parts of the text may give rise to several of the differences we have found. The paper will investigate whether this is the case. We will present an analysis of the vocabulary of both authors differentiating between dialogue, narrator's text, and ‘erlebte Rede' (narrated monologue). We will also list other possibly differentiating elements and test whether these play a part in the contrast we discovered by using Yule's K and Burrows's Delta. This qualitative phase in the research is meant to yield an overview of elements contributing to the (quantitative) contrast on the one hand, and to lead us to a list of key elements in the lexicon of the two authors on the other. The list of actual differences will be the input for a new quantitative and qualitative literary analysis of the character and voice of Penninc and Vostaert. Furthermore, we will look forward to the next purely quantitative step we hope to take, in which the results of the above can help us to establish a formula for authorship distinction in the genre of Middle Dutch Arthurian Romance, and help us, so to speak, to leap from the mining to the modelling of the differences.