Toward Fine-grained Causality Reasoning and Question Answering

This thesis mainly studies the causality in natural language processing. Understanding causality is key to the success of NLP applications, especially in high-stakes domains. Causality comes in various perspectives such as enable and prevent that, despite their importance, have been largely ignored in the literature. In view of the lack of a...

First Impressions of Using Stack Overflow for Education in a Computer Science Bachelor Programme

Community Question Answering (CQA) platforms like Stack Over- flow enable gamified and moderated community-driven knowledge creation. We report on our experiences of introducing Stack Over- flow in our Computer Science BSc programme and explore whether these platforms can (1) reduce the workload of lecturers in answer- ing questions in large...

Conversational Search and Recommendation: Introduction to the Special Issue

An introduction to the special issue on conversational search and recommendation is presented in this article. While conversational search and recommendation has roots in early Information Retrieval (IR) research, the recent advances in automatic voice recognition and conversational agents have created increasing interest in this area. In...

Investigating the case of weak baselines in Ad-hoc Retrieval and Question Answering

Weak baselines have been present in Information Retrieval (IR) for<br/>decades. They have been associated with IR progress stagnation, baseline<br/>selection bias to publish results more readily, and models’ effectiveness<br/>reproducibility issues that hinder the validation of results by independent<br/>research teams. Weak baselines have been...

Question Retrieval based on Community Question Answering: Baseline Selection among Retrieval Models on two Datasets

Community question answering (CQA) platforms provide a social environment for users to share knowledge online. Users can submit complex and subjective questions on CQA platforms and then derive the desired answer from other community users. A large number of user-generated data has been produced by various CQA sites (e.g., Quora, StackExchange)...

Word Embedding Models for Query Expansion in Answer Passage Retrieval

With the increasing popularity of mobile and voice-assisted, extracting short and precise answer passages to open-domain questions is becoming an increasingly important information retrieval (IR) task. The recently released large-scale corpus for answer passage retrieval—WikiPassageQA—was shown to be challenging for both traditional retrieval...

Question answering with the RoboTutor Nao

This thesis project worked towards extending the interactive capabilities of the RoboTutor Nao, by enabling it to answers natural language questions about topics such as computers, robots and the Nao itself. The main questions we focused on were 1) what a system for answering questions in Dutch and intended for elementary school age children...

Asking the right question in collaborative O&A systems

Collaborative Question Answering (cQA) platforms are a very popular repository of crowd-generated knowledge. By formulating questions, users express needs that other members of the cQA community try to collaboratively satisfy. Poorly formulated questions are less likely to receive useful responses, thus hindering the overall knowledge generation...

Enhanced Question Classification with Optimal Combination of Features

An important component of question answering systems is question classification. The task of question classification is to predict the entity type of the answer of a natural language question. Question classification is typically done using machine learning techniques. Different lexical, syntactical and semantic features can be extracted from a...

A Survey of State-of-the-Art Methods on Question Classification

The task of question classification (QC) is to predict the entity type of a question which is written in natural language. This is done by classifying the question to a category from a set of predefined categories. Question classification is an important component of question answering systems and it attracted a notable amount of research since...