Information retrieval systems are built to handle texts as topical items: texts are tabulated by occurrence frequencies of content words in them, under the assumption that text topic is reasonably well modeled by content word occurrence. But texts have several interesting characteristics beyond topic. The experiments described in this text investigate stylistic variation. Roughly put, style is the difference between two ways of saying the same thing -- and systematic stylistic variation can be used to characterize the genre of documents. These experiments investigate if stylistic information is distinguishable using simple language engineering methods, and if in that case this type of information can be used to improve information retrieval systems.

. Texts exhibit considerable stylistic variation. This paper reports an experiment where a corpus of documents (N= 75 000) is analyzed using various simple stylistic metrics. A subset (n = 1000) of the corpus has been previously assessed to be relevant for answering given information retrieval queries. The experiment shows that this subset differs significantly from the rest of the corpus in terms of the stylistic metrics studied. 1 Introduction Texts vary not only by topic. Stylistic variation between texts of the same topic is often at least as noticeable as the topical variation between texts of different topic but same genre or variety; style is, broadly defined, the difference between two ways of saying the same thing. Stylistic variation in a given text, given the liberal definition above, can occur in many ways and on many linguistic levels: lexical choice, choice of syntactic structures, choice of cohesion markers on a textual level, and so forth. Some choices are constrained ...

ing and Summarization : : : : : : : : : : : : : : : : : : : 19 1.4.8 How textuality could be utilized better : : : : : : : : : : : : : : : 19 1.5 Requests and queries: Dialog : : : : : : : : : : : : : : : : : : : : : : : : : 20 1.5.1 Boolean and probablistic approaches : : : : : : : : : : : : : : : : 20 1.6 Information Access Processes: Texts more than are : : : : : : : : : : : : 21 1.6.1 Typical query processing : : : : : : : : : : : : : : : : : : : : : : : 21 1.6.2 Beyond single queries : : : : : : : : : : : : : : : : : : : : : : : : : 1.6.3 Query expansion : : : : : : : : : : : : : : : : : : : : : : : : : : : 22 1.6.4 Relevance Feedback : : : : : : : : : : : : : : : : : : : : : : : : : : 23 1.6.5 Other qualities of text : : : : : : : : : : : : : : : : : : : : : : : : 23 1.7 Texts are sometimes written in other languages than English : : : : : : : 23 1.8 The contribution to linguistics : : : : : : : : : : : : : : : : : : : : : : : : 24 1.9 Conclusions: open research questions : : :...

Abstract T his chapter argues for more informed target metrics for the statistical processing of stylistic variation in text collections. Much as operationalized relevance proved a useful goal to strive for in information retrieval, research in textual stylistics, whether application oriented or philologically inclined, needs goals formulated in terms of pertinence, relevance, and utility—notions that agree with reader experience of text. Differences readers are aware of are mostly based on utility—not on textual characteristics per se. Mostly, readers report stylistic differences in terms of genres. Genres, while vague and undefined, are well-established and talked about: very early on, readers learn to distinguish genres. This chapter discusses variation given by genre, and contrasts it to variation occasioned by individual choice. 1.1 Stylistic variation in text Texts are much more than what they are about. Authors make choices when they write a: they decide how to organize the material they have planned to introduce; they select amongst available synonyms and syntactic constructions; they target an intended audience for the text. Authors will make their choices in various ways and for various reasons: based on personal preferences, on their view of the reader, and on what they know and like about other similar texts. These choices are observable to the reader in the form of stylistic variation, as the difference between two ways of saying the same thing. On a surface level this variation is quite obvious, as the choice between items in a vocabulary, between types of syntactical constructions, between the various ways a