77,796 research outputs found
Citation metrics for legal information retrieval: scholars and practitioners intertwined?
This paper examines citations in legal documents in the context of bibliometric-enhanced legal information retrieval. It is suggested that users of legal information retrieval systems wish to see both scholarly and non-scholarly information, and legal information retrieval systems are developed to be used by both scholarly and non-scholarly users. Since the use of citations in building arguments plays an important role in the legal domain, bibliometric information (such as citations) is an instrument to enhance legal information retrieval systems. This paper examines, through literature and data analysis, whether a bibliometric-enhanced ranking for legal information retrieval should consider both scholarly and non-scholarly publications, and whether this ranking could serve both user groups, or whether a distinction needs to be made.Our literature analysis suggests that for legal documents, there is no strict separation between scholarly and non-scholarly documents. There is no clear mark by which the two groups can be separated, and in as far as a distinction can be made, literature shows that both scholars and practitioners (non-scholars) use both types.We perform a data analysis to analyze this finding for legal information retrieval in practice, using citation and usage data from a legal search engine in the Netherlands. We first create a method to classify legal documents as either scholarly or non-scholarly based on criteria found in the literature. We then semi-automatically analyze a set of seed documents and register by what (type of) documents they are cited. This resulted in a set of 52 cited (seed) documents and 3086 citing documents. Based on the affiliation of users of the search engine, we analyzed the relation between user group and document type.Our data analysis confirms the literature analysis and shows much cross-citations between scholarly and non-scholarly documents. In addition, we find that scholarly users often open non-scholarly documents and vice versa. Our results suggest that for use in legal information retrieval systems citations in legal documents measure part of a broad scope of impact, or relevance, on the entire legal field. This means that for bibliometric-enhanced ranking in legal information retrieval, both scholarly and non-scholarly documents should be considered. The disregard by both scholarly and non-scholarly users of the distinction between scholarly and non-scholarly publications also suggests that the affiliation of the user is not likely a suitable factor to differentiate rankings on. The data in combination with literature suggests that a differentiation on user intent might be more suitable.Algorithms and the Foundations of Software technolog
Part of Speech Based Term Weighting for Information Retrieval
Automatic language processing tools typically assign to terms so-called
weights corresponding to the contribution of terms to information content.
Traditionally, term weights are computed from lexical statistics, e.g., term
frequencies. We propose a new type of term weight that is computed from part of
speech (POS) n-gram statistics. The proposed POS-based term weight represents
how informative a term is in general, based on the POS contexts in which it
generally occurs in language. We suggest five different computations of
POS-based term weights by extending existing statistical approximations of term
information measures. We apply these POS-based term weights to information
retrieval, by integrating them into the model that matches documents to
queries. Experiments with two TREC collections and 300 queries, using TF-IDF &
BM25 as baselines, show that integrating our POS-based term weights to
retrieval always leads to gains (up to +33.7% from the baseline). Additional
experiments with a different retrieval model as baseline (Language Model with
Dirichlet priors smoothing) and our best performing POS-based term weight, show
retrieval gains always and consistently across the whole smoothing range of the
baseline
Characterizing Question Facets for Complex Answer Retrieval
Complex answer retrieval (CAR) is the process of retrieving answers to
questions that have multifaceted or nuanced answers. In this work, we present
two novel approaches for CAR based on the observation that question facets can
vary in utility: from structural (facets that can apply to many similar topics,
such as 'History') to topical (facets that are specific to the question's
topic, such as the 'Westward expansion' of the United States). We first explore
a way to incorporate facet utility into ranking models during query term score
combination. We then explore a general approach to reform the structure of
ranking models to aid in learning of facet utility in the query-document term
matching phase. When we use our techniques with a leading neural ranker on the
TREC CAR dataset, our methods rank first in the 2017 TREC CAR benchmark, and
yield up to 26% higher performance than the next best method.Comment: 4 pages; SIGIR 2018 Short Pape
Optimal Information Retrieval with Complex Utility Functions
Existing retrieval models all attempt to optimize one single utility function, which is often based on the topical relevance of a document with respect to a query. In real applications, retrieval involves more complex utility functions that may involve preferences on several different dimensions. In this paper, we present a general optimization framework for retrieval with complex utility functions. A query language is designed according to this framework to enable users to submit complex queries. We propose an efficient algorithm for retrieval with complex utility functions based on the a-priori algorithm. As a case study, we apply our algorithm to a complex utility retrieval problem in distributed IR. Experiment results show that our algorithm allows for flexible tradeoff between multiple retrieval criteria. Finally, we study the efficiency issue of our algorithm on simulated data
Foreground and background text in retrieval
Our hypothesis is that certain clauses have foreground functions in text,
while other clauses have background functions and that these functions are
expressed or reflected in the syntactic structure of the clause.
Presumably these clauses will have differing utility for automatic
approaches to text understanding; a summarization system might want to
utilize background clauses to capture commonalities between numbers of
documents while an indexing system might use foreground clauses in order to
capture specific characteristics of a certain document
Evaluating the retrieval effectiveness of Web search engines using a representative query sample
Search engine retrieval effectiveness studies are usually small-scale, using
only limited query samples. Furthermore, queries are selected by the
researchers. We address these issues by taking a random representative sample
of 1,000 informational and 1,000 navigational queries from a major German
search engine and comparing Google's and Bing's results based on this sample.
Jurors were found through crowdsourcing, data was collected using specialised
software, the Relevance Assessment Tool (RAT). We found that while Google
outperforms Bing in both query types, the difference in the performance for
informational queries was rather low. However, for navigational queries, Google
found the correct answer in 95.3 per cent of cases whereas Bing only found the
correct answer 76.6 per cent of the time. We conclude that search engine
performance on navigational queries is of great importance, as users in this
case can clearly identify queries that have returned correct results. So,
performance on this query type may contribute to explaining user satisfaction
with search engines
Machine Learning in Automated Text Categorization
The automated categorization (or classification) of texts into predefined
categories has witnessed a booming interest in the last ten years, due to the
increased availability of documents in digital form and the ensuing need to
organize them. In the research community the dominant approach to this problem
is based on machine learning techniques: a general inductive process
automatically builds a classifier by learning, from a set of preclassified
documents, the characteristics of the categories. The advantages of this
approach over the knowledge engineering approach (consisting in the manual
definition of a classifier by domain experts) are a very good effectiveness,
considerable savings in terms of expert manpower, and straightforward
portability to different domains. This survey discusses the main approaches to
text categorization that fall within the machine learning paradigm. We will
discuss in detail issues pertaining to three different problems, namely
document representation, classifier construction, and classifier evaluation.Comment: Accepted for publication on ACM Computing Survey
Information Retrieval Models
Many applications that handle information on the internet would be completely\ud
inadequate without the support of information retrieval technology. How would\ud
we find information on the world wide web if there were no web search engines?\ud
How would we manage our email without spam filtering? Much of the development\ud
of information retrieval technology, such as web search engines and spam\ud
filters, requires a combination of experimentation and theory. Experimentation\ud
and rigorous empirical testing are needed to keep up with increasing volumes of\ud
web pages and emails. Furthermore, experimentation and constant adaptation\ud
of technology is needed in practice to counteract the effects of people that deliberately\ud
try to manipulate the technology, such as email spammers. However,\ud
if experimentation is not guided by theory, engineering becomes trial and error.\ud
New problems and challenges for information retrieval come up constantly.\ud
They cannot possibly be solved by trial and error alone. So, what is the theory\ud
of information retrieval?\ud
There is not one convincing answer to this question. There are many theories,\ud
here called formal models, and each model is helpful for the development of\ud
some information retrieval tools, but not so helpful for the development others.\ud
In order to understand information retrieval, it is essential to learn about these\ud
retrieval models. In this chapter, some of the most important retrieval models\ud
are gathered and explained in a tutorial style
Multimodal music information processing and retrieval: survey and future challenges
Towards improving the performance in various music information processing
tasks, recent studies exploit different modalities able to capture diverse
aspects of music. Such modalities include audio recordings, symbolic music
scores, mid-level representations, motion, and gestural data, video recordings,
editorial or cultural tags, lyrics and album cover arts. This paper critically
reviews the various approaches adopted in Music Information Processing and
Retrieval and highlights how multimodal algorithms can help Music Computing
applications. First, we categorize the related literature based on the
application they address. Subsequently, we analyze existing information fusion
approaches, and we conclude with the set of challenges that Music Information
Retrieval and Sound and Music Computing research communities should focus in
the next years
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