Abstract

In this report, we present details about the participation of IIIT Hyderabad in Guided Summarization and Knowledge Base Population tracks at TAC 2011. we have enhanced our summarization system with knowledge based measures. Wikipedia based extraction methods and topic modelling are used to score sentences in guided summarization track. For multilingual summarization task, we investigated the HAL (Hyperspace Analogue to Language Model) where we created a semantic space from word co-occurrences. We show that the results obtained with this unsupervised language independent method are competitive with other state-of-the-art systems. For monolingual and multilingual entity linking task, we extended our previous year’s model to a light weight language independent system without utilizing any other external knowledge or resource.

Abstract

Sentiment mining and classification plays an important role in predicting what people think about products, places, etc. In this piece of work, using basic NLP Techniques like NGram, POS-Tagged NGram we classify movie and product reviews broadly into two polarities: Positive and Negative. We propose a model to address the problem of determining whether a review is positive or negative, we experiment and use several machine learning algorithms Naive Bayes (NB), Multi-Layer Perceptron (MLP), Support Vector Machine (SVM) to have a comparative study of the performance of the method we devised in this work. Along with this we also did negation handling and observed improvements in classification. The algorithm we proposed achieved an average accuracy of 78.32% on movie and 70.06% on multi-category dataset. In this paper we focus on the collective study of Ngram and POS tagged information available in the reviews.

Abstract

The world of E-commerce is expanding, posing a large arena of products, their descriptions, customer and professional reviews that are pertinent to them. Most of the product attribute extraction techniques in literature work on structured descriptions using several text analysis tools. However, attributes in these descriptions are limited compared to those in customer reviews of a product, where users discuss deeper and more specific attributes. In this paper, we propose a novel supervised domain independent model for product attribute extraction from user reviews. The user generated content contains unstructured and semi-structured text where conventional language grammar dependent tools like parts-of-speech taggers, named entity recognizers, parsers do not perform at expected levels. We used Wikipedia and Web to identify product attributes from customer reviews and achieved F1score of 0.73.

Abstract

In web search, understanding the user intent plays an important role in improving search experience of the end users. Such an intent can be represented by the categories which the user query belongs to. In this work, we propose an information retrieval based approach to query categorization with an emphasis on learning category rankings. To carry out categorization we first represent a category by web documents (from Open Directory Project) that describe the semantics of the category. Then, we learn the category rankings for the queries using 'learning to rank' techniques. To show that the results obtained are consistent and do not vary across datasets, we evaluate our approach on two datasets including the publicly available KDD Cup dataset. We report an overall improvement of 20% on all evaluation metrics (precision, recall and F-measure) over two baselines: a text categorization baseline and an unsupervised IR baseline.

Abstract

Finding similar patents is a challenging task in patent information retrieval. A patent application is often a starting point to find similar inventions. Keyword search for similar patents requires significant domain expertise and may not fetch relevant results. We propose a novel representation for patents and use a two stage approach to find similar patents. Each patent is represented as an IPC class vector. Citation network of patents is used to propagate these vectors from a node (patent) to its neighbors (cited patents). Thus, each patent is represented as a weighted combination of its IPC information as well as of its neighbors. A query patent is represented as a vector using its IPC information and similar patents can be simply found by comparing this vector with vectors of patents in the corpus. Text based search is used to re-rank this solution set to improve precision. We experiment with two similarity measures and re-ranking strategies to empirically show that our representation is effective in improving both precision and recall of queries of CLEF-2011 dataset.

Abstract

This paper presents a language-independent Multilingual Document Clustering (MDC) approach on comparable corpora. Named entites (NEs) such as persons, locations, organizations play a major role in measuring the document similarity. We propose a method to identify these NEs present in under-resourced Indian languages (Hindi and Marathi) using the NEs present in English, which is a high resourced language. The identified NEs are then utilized for the formation of multilingual document clusters using the Bisecting k-means clustering algorithm. We didn’t make use of any non-English linguistic tools or resources such as WordNet, Part-Of-Speech tagger, bilingual dictionaries, etc., which makes the proposed approach completely language-independent. Experiments are conducted on a standard dataset provided by FIRE for their 2010 Ad-hoc Cross-Lingual document retrieval task on Indian languages. We have considered English, Hindi and Marathi news datasets for our experiments. The system is evaluated using F-score, Purity and Normalized Mutual Information measures and the results obtained are encouraging.

Abstract

This paper describes a large scale system for Cross Language Information Access(CLIA) which will help accessing information available in a language that is different from the language in which a query or information need is expressed. We specifically focus on Telugu to English and Hindi CLIA system. For a query given in Telugu, this system retrieves information available in English and Hindi. It also tries to present that information back in Telugu using several information access technologies such as: Information Extraction, Summarization and Machine Translation. This system was developed at IIIT Hyderabad, in the context of a larger project funded by Ministry of Communication and Information Technology executed by a consortium of ten Universities and research organizations covering six Indian languages for input and English and Hindi as target languages.

Abstract

In this paper we describe experiments conducted for CLEFIP 2011 Prior Art Retrieval track. We examined the impact of 1) using key phrase extraction to generate queries from input patent and 2) the use of citation network and (International Patent Classification) IPC class vector in ranking patents. Variations of a popular key phrase extraction technique were explored for extracting and scoring terms of query patent. These terms are used as queries to retrieve similar patents. In the second approach, we use a two stage retrieval model to find similar patents. Each patent is represented as an IPC class vector. Citation network of patents is used to propagate these vectors from a node (patent) to its neighbors (cited patents). Similar patents are found by comparing query vector with vectors of patents in the corpus. Text based search is used to re-rank this solution set to improve precision. Two-stage system is used to retrieve and rank patents. Finally, we also extract and add citations present within the text of a query patent to the result set. Adding these citations (present in query patent text) to the results shows significant improvement in Mean Average Precision (MAP).

Abstract

Context in a web-based social system can be a valuable source of user information. On Twitter, context can be derived from user interactions, content streams and friendship. In this paper we focus on extracting user context by means of conversation patterns and user-generated twitter lists. We present a novel approach which utilizes just the context to extract twitter users’ topics of interest. Our approach achieved a precision of 84% indicating that user context can be exploited for topic information.

Abstract

Verbose web queries are often descriptive in nature where a term based search engine is unable to distinguish between the essential and noisy words, which can result in a drift from the user intent. We present a randomized query reduction technique that builds on an earlier learning to rank based approach. The proposed technique randomly picks only a small set of samples, instead of the exponentially many sub-queries, thus being fast enough to be useful for web search engines, while still covering wide sub-query space.