1,336 research outputs found
Multilingual adaptive search for digital libraries
This paper describes a framework for Adaptive Multilingual Information Retrieval (AMIR) which allows multilingual resource discovery and delivery using on-the-fly machine translation of documents and queries. Result documents
are presented to the user in a contextualised manner. Challenges and affordances of both Adaptive and Multilingual IR, with a particular focus on Digital Libraries, are detailed. The framework components are motivated by a series of results from experiments on query logs and documents from The European Library. We conclude that factoring adaptivity and multilinguality aspects into the search process can enhance the user’s experience with online Digital Libraries
Document expansion for image retrieval
Successful information retrieval requires e�ective matching
between the user's search request and the contents of relevant
documents. Often the request entered by a user may
not use the same topic relevant terms as the authors' of the
documents. One potential approach to address problems
of query-document term mismatch is document expansion
to include additional topically relevant indexing terms in a
document which may encourage its retrieval when relevant
to queries which do not match its original contents well. We
propose and evaluate a new document expansion method
using external resources. While results of previous research
have been inconclusive in determining the impact of document
expansion on retrieval e�ectiveness, our method is
shown to work e�ectively for text-based image retrieval of
short image annotation documents. Our approach uses the
Okapi query expansion algorithm as a method for document
expansion. We further show improved performance can be
achieved by using a \document reduction" approach to include
only the signi�cant terms in a document in the expansion
process. Our experiments on the WikipediaMM task at
ImageCLEF 2008 show an increase of 16.5% in mean average
precision (MAP) compared to a variation of Okapi BM25 retrieval
model. To compare document expansion with query
expansion, we also test query expansion from an external resource
which leads an improvement by 9.84% in MAP over
our baseline. Our conclusion is that the document expansion
with document reduction and in combination with query expansion
produces the overall best retrieval results for shortlength
document retrieval. For this image retrieval task, we
also concluded that query expansion from external resource
does not outperform the document expansion method
Sub-word indexing and blind relevance feedback for English, Bengali, Hindi, and Marathi IR
The Forum for Information Retrieval Evaluation (FIRE) provides document collections, topics, and relevance assessments for information retrieval (IR) experiments on Indian languages. Several research questions are explored in this paper: 1. how to create create a simple, languageindependent corpus-based stemmer, 2. how to identify sub-words and which types of sub-words are suitable as indexing units, and 3. how to apply blind relevance feedback on sub-words and how feedback term selection is affected by the type of the indexing unit. More than 140 IR experiments are conducted using the BM25 retrieval model on the topic titles and descriptions (TD) for the FIRE 2008 English, Bengali, Hindi, and Marathi document collections. The major findings are: The corpus-based stemming approach is effective as a knowledge-light
term conation step and useful in case of few language-specific resources. For English, the corpusbased
stemmer performs nearly as well as the Porter stemmer and significantly better than the baseline of indexing words when combined with query expansion. In combination with blind relevance feedback, it also performs significantly better than the baseline for Bengali and Marathi IR.
Sub-words such as consonant-vowel sequences and word prefixes can yield similar or better performance in comparison to word indexing. There is no best performing method for all languages. For English, indexing using the Porter stemmer performs best, for Bengali and Marathi, overlapping 3-grams obtain the best result, and for Hindi, 4-prefixes yield the highest MAP. However, in combination with blind relevance feedback using 10 documents and 20 terms, 6-prefixes for English and 4-prefixes for Bengali, Hindi, and Marathi IR yield the highest MAP. Sub-word identification is a general case of decompounding. It results in one or more index terms for a single word form and increases the number of index terms but decreases their average length. The corresponding retrieval experiments show that relevance feedback on sub-words benefits from
selecting a larger number of index terms in comparison with retrieval on word forms. Similarly, selecting the number of relevance feedback terms depending on the ratio of word vocabulary size to sub-word vocabulary size almost always slightly increases information retrieval effectiveness
compared to using a fixed number of terms for different languages
Exploring Metaphorical Senses and Word Representations for Identifying Metonyms
A metonym is a word with a figurative meaning, similar to a metaphor. Because
metonyms are closely related to metaphors, we apply features that are used
successfully for metaphor recognition to the task of detecting metonyms. On the
ACL SemEval 2007 Task 8 data with gold standard metonym annotations, our system
achieved 86.45% accuracy on the location metonyms. Our code can be found on
GitHub.Comment: 9 pages, 8 pages conten
Cross-Language Question Re-Ranking
We study how to find relevant questions in community forums when the language
of the new questions is different from that of the existing questions in the
forum. In particular, we explore the Arabic-English language pair. We compare a
kernel-based system with a feed-forward neural network in a scenario where a
large parallel corpus is available for training a machine translation system,
bilingual dictionaries, and cross-language word embeddings. We observe that
both approaches degrade the performance of the system when working on the
translated text, especially the kernel-based system, which depends heavily on a
syntactic kernel. We address this issue using a cross-language tree kernel,
which compares the original Arabic tree to the English trees of the related
questions. We show that this kernel almost closes the performance gap with
respect to the monolingual system. On the neural network side, we use the
parallel corpus to train cross-language embeddings, which we then use to
represent the Arabic input and the English related questions in the same space.
The results also improve to close to those of the monolingual neural network.
Overall, the kernel system shows a better performance compared to the neural
network in all cases.Comment: SIGIR-2017; Community Question Answering; Cross-language Approaches;
Question Retrieval; Kernel-based Methods; Neural Networks; Distributed
Representation
DCU@TRECMed 2012: Using ad-hoc baselines for domain-specific retrieval
This paper describes the first participation of DCU in the TREC Medical Records Track (TRECMed). We performed some initial experiments on the 2011 TRECMed data based on the BM25 retrieval model. Surprisingly, we found that the standard BM25 model with default parameters, performs comparable to the best automatic runs submitted to TRECMed 2011 and would have resulted in rank four out of 29 participating groups. We expected that some form of domain adaptation would increase performance. However, results on the 2011 data proved otherwise: concept-based query expansion decreased performance, and filtering and reranking by term proximity also decreased performance slightly. We submitted four runs based on the BM25 retrieval model to TRECMed 2012 using standard BM25, standard query expansion, result filtering, and concept-based query expansion. Official results for 2012 confirm that domain-specific knowledge does not increase performance compared to the BM25 baseline as applied by us
Identifying effective translations for cross-lingual Arabic-to-English user-generated speech search
Cross Language Information Retrieval
(CLIR) systems are a valuable tool to enable speakers of one language to search for
content of interest expressed in a different
language. A group for whom this is of particular interest is bilingual Arabic speakers
who wish to search for English language
content using information needs expressed
in Arabic queries. A key challenge in
CLIR is crossing the language barrier
between the query and the documents.
The most common approach to bridging
this gap is automated query translation,
which can be unreliable for vague or short
queries. In this work, we examine the
potential for improving CLIR effectiveness
by predicting the translation effectiveness
using Query Performance Prediction (QPP)
techniques. We propose a novel QPP
method to estimate the quality of translation for an Arabic-Engish Cross-lingual
User-generated Speech Search (CLUGS)
task. We present an empirical evaluation
that demonstrates the quality of our method
on alternative translation outputs extracted
from an Arabic-to-English Machine Translation system developed for this task. Finally, we show how this framework can be
integrated in CLUGS to find relevant translations for improved retrieval performance
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