Alternative ways to estimate change points in multinomial sequences. An application to an authorship attribution problem

The statistical analysis of literary style is the part of stylometry that compares measurable characteristics in a text that are rarely controlled by the author, with those in other texts. When the goal is to settle authorship questions, these characteristics should relate to the author’s style and not to the genre, epoch or editor, and they should be such that their variation between authors is larger than the variation within comparable texts from the same author. For an overview of the literature on stylometry and some of the techniques involved, see for example Mosteller and Wallace (1964, 82), Herdan (1964), Morton (1978), Holmes (1985), Oakes (1998) or Lebart, Salem and Berry (1998). Tirant lo Blanc, a chivalry book, is the main work in catalan literature and it was hailed to be “the best book of its kind in the world” by Cervantes in Don Quixote. Considered by writters like Vargas Llosa or Damaso Alonso to be the first modern novel in Europe, it has been translated several times into Spanish, Italian and French, with modern English translations by Rosenthal (1996) and La Fontaine (1993). The main body of this book was written between 1460 and 1465, but it was not printed until 1490. There is an intense and long lasting debate around its authorship sprouting from its first edition, where its introduction states that the whole book is the work of Martorell (1413?-1468), while at the end it is stated that the last one fourth of the book is by Galba (?-1490), after the death of Martorell. Some of the authors that support the theory of single authorship are Riquer (1990), Chiner (1993) and Badia (1993), while some of those supporting the double authorship are Riquer (1947), Coromines (1956) and Ferrando (1995). For an overview of this debate, see Riquer (1990). Neither of the two candidate authors left any text comparable to the one under study, and therefore discriminant analysis can not be used to help classify chapters by author. By using sample texts encompassing about ten percent of the book, and looking at word length and at the use of 44 conjunctions, prepositions and articles, Ginebra and Cabos (1998) detect heterogeneities that might indicate the existence of two authors. By analyzing the diversity of the vocabulary, Riba and Ginebra (2000) estimates that stylistic boundary to be near chapter 383. Following the lead of the extensive literature, this paper looks into word length, the use of the most frequent words and into the use of vowels in each chapter of the book. Given that the features selected are categorical, that leads to three contingency tables of ordered rows and therefore to three sequences of multinomial observations. Section 2 explores these sequences graphically, observing a clear shift in their distribution. Section 3 describes the problem of the estimation of a suden change-point in those sequences, in the following sections we propose various ways to estimate change-points in multinomial sequences; the method in section 4 involves fitting models for polytomous data, the one in Section 5 fits gamma models onto the sequence of Chi-square distances between each row profiles and the average profile, the one in Section 6 fits models onto the sequence of values taken by the first component of the correspondence analysis as well as onto sequences of other summary measures like the average word length. In Section 7 we fit models onto the marginal binomial sequences to identify the features that distinguish the chapters before and after that boundary. Most methods rely heavily on the use of generalized linear models

gvSIG Mobile: nuevas funcionalidades del SIG Libre para PDA

gvSIG Mobile, la versión de gvSIG para dispositivos móviles presenta su nueva versión que incluye las esperadas funcionalidades de creación de nuevas entidades geográficas y utilización de formularios personalizados para edición de datos, además de nuevos formatos de datos vectoriales (GML, KML, GPX) y sistemas de referencia. Funcionalidades que se suman a las capacidades de visor de cartografía (ECW, SHP, WMS) y sistema de localización mediante GPS que ya posee. gvSIG Mobile está siendo desarrollado por Prodevelop, la Universitat de València e Iver para la Conselleria d’Infraestructures i Transport de la Generalitat Valenciana y se distribuye con una licencia GPL

Research and teaching: a holy or an unholy alliance?

Much of the self-image of the Western university hangs on the idea that research and teaching are intimately connected. The central axiom here is that research and teaching are mutually supportive of each other. An institution lacking such a set of relationships between research and teaching falls short of what it means to be a university. This set of beliefs raises certain questions: Is it the case that the presence of such a mutually supportive set of relationships between research and teaching is a necessary condition of the fulfilment of the idea of the university? (A conceptual question). And is it true that, in practice today, such a mutually supportive set of relationships between research and teaching characterises universities? (An empirical question). In my talk, I want to explore these matters in a critical vein. I shall suggest that: a) In practice today, such a mutually supportive set of relationships between research and teaching is in jeopardy. Far from supporting each other, very often research and teaching contend against each other. Research and teaching are becoming two separate ideologies, with their own interest structures. b) Historically, the supposed tight link between research and teaching is both of recent origin and far from universally achieved in universities. Institutional separateness between research and teaching is and has been evident, both across institutions and even across departments in the same institution. c) Conceptually, research and teaching are different activities: each is complex and neither is reducible to the other. In theory, therefore, research and teaching may be said to constitute a holy alliance but in practice, we see more of an unholy alliance. If, then, in an ideal world, a positive relationship between research and teaching is still a worthwhile goal, how might it be construed and worked for? Seeing research and teaching as two discrete and unified sets of activity is now inadequate. Much better is a construal of research and teaching as themselves complexes, as intermingling pools of activity helping to form the liquid university that is emerging today. On this view, research and teaching are fluid spaces, ever on the move, taking up new shapes, and themselves dividing and reforming, as the university reworks its own destiny in modern society. On such a perspective, working out a productive relationship between research and teaching is a complex project. This is an alliance that is neither holy nor unholy. It is an uneasy alliance, with temporary accommodations and continuous new possibilities

En la prehistòria dels hisendats. De senyors útils a propietaris (vegueria de Girona, 1486-1730)

A la vegueria de Girona, entre 1486 i 1730, es produeix el procés de formació històrica d'un grup social que sorgit de la pagesia s'anirà diferenciant progressivament d'aquesta: els senyors útils i propietaris de masos. Aquest grup social basa el seu poder econòmic i polític en l'acumulació de masos: font de rendes i font de l'estatus social assolit dins la parròquia i la universitat on fixa la seva residència. El seu pes social el manifesta a través dels seus espais de sociabilitat (especialment la parròquia, veritable espai de representació), però també manifesta la seva posició de preeminència, fet que pot abocar als conflictes amb el conjunt de la comunitat. Un conflicte que es planteja en termes de diferenciació dels uns i d'igualtat dels altres. És l'enfrontament entre dues visions de la societat: l'individualisme enfront el comunitarisme.