title: Concept-based Text Clustering

authors: Huang, Lan

subjects: clustering

abstract: Thematic organization of text is a natural practice of humans and a crucial task for today's vast repositories. Clustering automates this by assessing the similarity between texts and organizing them accordingly, grouping like ones together and separating those with different topics. Clusters provide a comprehensive logical structure that facilitates exploration, search and interpretation of current texts, as well as organization of future ones. Automatic clustering is usually based on words. Text is represented by the words it mentions, and thematic similarity is based on the proportion of words that texts have in common. The resulting bag-of-words model is semantically ambiguous and undesirably orthogonal|it ignores the connections between words. This thesis claims that using concepts as the basis of clustering can significantly improve effectiveness. Concepts are defined as units of knowledge. When organized according to the relations among them, they form a concept system. Two concept systems are used here: WordNet, which focuses on word knowledge, and Wikipedia, which encompasses world knowledge. We investigate a clustering procedure with three components: using concepts to represent text; taking the semantic relations among them into account during clustering; and learning a text similarity measure from concepts and their relations. First, we demonstrate that concepts provide a succinct and informative representation of the themes in text, exemplifying this with the two concept systems. Second, we define methods for utilizing concept relations to enhance clustering by making the representation models more discriminative and extending thematic similarity beyond surface overlap. Third, we present a similarity measure based on concepts and their relations that is learned from a small number of examples, and show that it both predicts similarity consistently with human judgement and improves clustering. The thesis provides strong support for the use of concept-based representations instead of the classic bag-of-words model.

text: Concept-based Text Clustering Thematic organization of text is a natural practice of humans and a crucial task for today's vast repositories. Clustering automates this by assessing the similarity between texts and organizing them accordingly, grouping like ones together and separating those with different topics. Clusters provide a comprehensive logical structure that facilitates exploration, search and interpretation of current texts, as well as organization of future ones. Automatic clustering is usually based on words. Text is represented by the words it mentions, and thematic similarity is based on the proportion of words that texts have in common. The resulting bag-of-words model is semantically ambiguous and undesirably orthogonal|it ignores the connections between words. This thesis claims that using concepts as the basis of clustering can significantly improve effectiveness. Concepts are defined as units of knowledge. When organized according to the relations among them, they form a concept system. Two concept systems are used here: WordNet, which focuses on word knowledge, and Wikipedia, which encompasses world knowledge. We investigate a clustering procedure with three components: using concepts to represent text; taking the semantic relations among them into account during clustering; and learning a text similarity measure from concepts and their relations. First, we demonstrate that concepts provide a succinct and informative representation of the themes in text, exemplifying this with the two concept systems. Second, we define methods for utilizing concept relations to enhance clustering by making the representation models more discriminative and extending thematic similarity beyond surface overlap. Third, we present a similarity measure based on concepts and their relations that is learned from a small number of examples, and show that it both predicts similarity consistently with human judgement and improves clustering. The thesis provides strong support for the use of concept-based representations instead of the classic bag-of-words model.

year: 2011

title: New Zealand’s Regulation of Internet Child Pornography

authors: Ball, Tawhana

abstract: The Internet has revolutionised the exchange of all forms of information, including that of an issue of great concern: child pornography. The consumption of child pornography is not a legislative or punitive problem. It is a law enforcement issue exacerbated by the main medium of supply, the Internet. The problem of the regulation of child pornography on the Internet has no universal answer. The solution to this concern will require a modulated response which will enable law enforcement agencies to adequately counter every aspect of the issue. This thesis examines New Zealand’s classification system and the primary statutory authority which prohibits the proliferation of child pornography, the Films, Videos, and Publications Classification Act 1993. 

Drawing on institutional, private and law enforcement narratives, this thesis investigates New Zealand’s current legal responses to the consumption of child pornography by way of the Internet. The intention of this investigation is to ascertain whether institutional responses could be improved and to make recommendations to assist law enforcement agencies to respond more effectively to this concern. Empirical data has been gathered from law enforcement personnel through qualitative research and has provided a privileged insight into the complexities of child pornography investigations. This qualitative empirical research confirmed that New Zealand’s child pornography legislation must be continually critiqued to ensure that it is keeping pace with technology. New Zealand’s institutional responses also need to be constantly evaluated to guarantee that the capacity of law enforcement agencies to respond to the problem of child pornography keeps pace with the main medium of supply, the Internet. Moreover, this thesis contends that all forms of child pornography should be outlawed because of its potential to cause harm to children and society. Although, the recommendations of this thesis do not constitute the definitive answer to the issue of child pornography on the Internet, each individual aspect of the recommendations constitutes a critical component of an overall response to this concern.

text: New Zealand’s Regulation of Internet Child Pornography The Internet has revolutionised the exchange of all forms of information, including that of an issue of great concern: child pornography. The consumption of child pornography is not a legislative or punitive problem. It is a law enforcement issue exacerbated by the main medium of supply, the Internet. The problem of the regulation of child pornography on the Internet has no universal answer. The solution to this concern will require a modulated response which will enable law enforcement agencies to adequately counter every aspect of the issue. This thesis examines New Zealand’s classification system and the primary statutory authority which prohibits the proliferation of child pornography, the Films, Videos, and Publications Classification Act 1993. 

Drawing on institutional, private and law enforcement narratives, this thesis investigates New Zealand’s current legal responses to the consumption of child pornography by way of the Internet. The intention of this investigation is to ascertain whether institutional responses could be improved and to make recommendations to assist law enforcement agencies to respond more effectively to this concern. Empirical data has been gathered from law enforcement personnel through qualitative research and has provided a privileged insight into the complexities of child pornography investigations. This qualitative empirical research confirmed that New Zealand’s child pornography legislation must be continually critiqued to ensure that it is keeping pace with technology. New Zealand’s institutional responses also need to be constantly evaluated to guarantee that the capacity of law enforcement agencies to respond to the problem of child pornography keeps pace with the main medium of supply, the Internet. Moreover, this thesis contends that all forms of child pornography should be outlawed because of its potential to cause harm to children and society. Although, the recommendations of this thesis do not constitute the definitive answer to the issue of child pornography on the Internet, each individual aspect of the recommendations constitutes a critical component of an overall response to this concern.

year: 2017

title: Lost in translation: western representations of Māori knowledge

authors: Mika, Carl Te Hira

abstract: We recently attended a conference at which a non-Māori presenter, drawing on a particular metaphor already established by Māori writers, related Māori natural world features to a research method. The presentation was useful because it highlighted several issues that call for our concern as Māori philosophers. In this article, we outline these concerns, which are: first, that a blunt response to such a presentation is not undertaken lightly from a Māori viewpoint; and, second, that the presenter’s talk exemplifies a wider problem of warping Māori concepts and labels to fit a Western philosophical approach. We call this latter problem ‘Translation’, because it involves moving the Māori world and its phenomena over into one that is palatable for policy and research. The aim of the article is not to single out the presenter, but rather to refer to his presentation in order to consider the prior issue of Translation. In cases where Translation occurs, a Māori critical philosophical stance is clearly needed, in order to both investigate the warping of Māori thought on which it relies, and review the place of Māori philosophy and philosophical response in the arena of educational research.

text: Lost in translation: western representations of Māori knowledge We recently attended a conference at which a non-Māori presenter, drawing on a particular metaphor already established by Māori writers, related Māori natural world features to a research method. The presentation was useful because it highlighted several issues that call for our concern as Māori philosophers. In this article, we outline these concerns, which are: first, that a blunt response to such a presentation is not undertaken lightly from a Māori viewpoint; and, second, that the presenter’s talk exemplifies a wider problem of warping Māori concepts and labels to fit a Western philosophical approach. We call this latter problem ‘Translation’, because it involves moving the Māori world and its phenomena over into one that is palatable for policy and research. The aim of the article is not to single out the presenter, but rather to refer to his presentation in order to consider the prior issue of Translation. In cases where Translation occurs, a Māori critical philosophical stance is clearly needed, in order to both investigate the warping of Māori thought on which it relies, and review the place of Māori philosophy and philosophical response in the arena of educational research.

year: 2017