Ontology-Based Question Answering System in Restricted Domain

The complexity of natural language presents difficult challenges that traditional Questions and Answers (Q&A) system such as Frequently Asked Questions, relied on the collective predefined questions and answers, unable to address. Traditional Q&A system is unable to retrieve exact answer in response to different kind of natural language questions asked by the user. Therefore, this paper aims to present an architecture of Ontology-based Question Answering (OQA) system, applied to library domain. The main task of OQA system is to parse question expressed in natural language with respect to restricted domain ontology and retrieve the matched answer. Restricted ontology model is designed as a knowledge base to assist the process based on the effective information derived from the questions. In addition, ontology matching algorithm is developed to deal with the questionanswer matching process. A case study is taken from the library of Sultanah Nur Zahirah of Universiti Malaysia Terengganu. A prototype of Sultanah Nur Zahirah Digital Learning ONtologybased FAQ System (SONFAQS) is developed. The experimental result shows that the architecture is feasible and significantly improves man-machine interaction by shortening the searching time

Selecting Contextual Peripheral Information for Answer Presentation: The Need for Pragmatic Models

This paper explores the possibility of pre-senting additional contextual information as a method of answer presentation Question An-swering. In particular the paper discusses the result of employing Bag of Words (BoW) and Bag of Concepts (BoC) models to retrieve contextual information from a Linked Data resource, DBpedia. DBpedia provides struc-tured information on wide variety of entities in the form of triples. We utilize the QALD question sets consisting of a 100 instances in the training set and another 100 in the testing set. The questions are categorized into single entity and multiple entity questions based on the number of entities mentioned in the ques-tion. The results show that both BoW (syn-tactic models) and BoC (semantic models) are not capable enough to select contextual infor-mation for answer presentation. The results further reveals that pragmatic aspects, in par-ticular, pragmatic intent and pragmatic infer-ence play a crucial role in contextual informa-tion selection in the answer presentation.

DSSim-ontology mapping with uncertainty

This paper introduces an ontology mapping system that is used with a multi agent ontology mapping framework in the context of question answering. Our mapping algorithm incorporates the Dempster Shafer theory of evidence into the mapping process in order to improve the correctness of the mapping. Our main objective was to assess how applying the belief function can improve correctness of the ontology mapping through combining the similarities which were originally created by both syntactic and semantic similarity algorithms. We carried out experiments with the data sets of the Ontology Alignment Evaluation Initiative 2006 which served as a test bed to assess both the strong and weak points of our system. The experiments confirm that our algorithm performs well with both concept and property names

A data mining approach to ontology learning for automatic content-related question-answering in MOOCs.

The advent of Massive Open Online Courses (MOOCs) allows massive volume of registrants to enrol in these MOOCs. This research aims to offer MOOCs registrants with automatic content related feedback to fulfil their cognitive needs. A framework is proposed which consists of three modules which are the subject ontology learning module, the short text classification module, and the question answering module. Unlike previous research, to identify relevant concepts for ontology learning a regular expression parser approach is used. Also, the relevant concepts are extracted from unstructured documents. To build the concept hierarchy, a frequent pattern mining approach is used which is guided by a heuristic function to ensure that sibling concepts are at the same level in the hierarchy. As this process does not require specific lexical or syntactic information, it can be applied to any subject. To validate the approach, the resulting ontology is used in a question-answering system which analyses students' content-related questions and generates answers for them. Textbook end of chapter questions/answers are used to validate the question-answering system. The resulting ontology is compared vs. the use of Text2Onto for the question-answering system, and it achieved favourable results. Finally, different indexing approaches based on a subject's ontology are investigated when classifying short text in MOOCs forum discussion data; the investigated indexing approaches are: unigram-based, concept-based and hierarchical concept indexing. The experimental results show that the ontology-based feature indexing approaches outperform the unigram-based indexing approach. Experiments are done in binary classification and multiple labels classification settings . The results are consistent and show that hierarchical concept indexing outperforms both concept-based and unigram-based indexing. The BAGGING and random forests classifiers achieved the best result among the tested classifiers

A teachable semi-automatic web information extraction system based on evolved regular expression patterns

This thesis explores Web Information Extraction (WIE) and how it has been used in decision making and to support businesses in their daily operations. The research focuses on a WIE system based on Genetic Programming (GP) with an extensible model to enhance the automatic extractor. This uses a human as a teacher to identify and extract relevant information from the semi-structured HTML webpages. Regular expressions, which have been chosen as the pattern matching tool, are automatically generated based on the training data to provide an improved grammar and lexicon. This particularly benefits the GP system which may need to extend its lexicon in the presence of new tokens in the web pages. These tokens allow the GP method to produce new extraction patterns for new requirements

AQUA - Ontology-based question answering system

This paper describes AQUA, an experimental question answering system. AQUA combines Natural Language Processing (NLP), Ontologies, Logic, and Information Retrieval technologies in a uniform framework. AQUA makes intensive use of an ontology in several parts of the question answering system. The ontology is used in the refinement of the initial query, the reasoning process, and in the novel similarity algorithm. The similarity algorithm, is a key feature of AQUA. It is used to find similarities between relations used in the translated query and relations in the ontological structures