With the huge amount of subjective contents in on-line documents, there is a clear need for an information retrieval system that supports retrieval of documents containing opinions about the topic expressed in a user’s query. In recent years, blogs, a new publishing medium, have attracted a large number of people to express personal opinions covering all kinds of topics in response to the real-world events. The opinionated nature of blogs makes them a new interesting research area for opinion retrieval. Identification and extraction of subjective contents from blogs has become the subject of several research projects. In this thesis, four novel methods are proposed to retrieve blog posts that express opinions about the given topics. The first method utilizes the Kullback-Leibler divergence (KLD) to weight the lexicon of subjective adjectives around query terms. Considering the distances between the query terms and subjective adjectives, the second method uses KLD scores of subjective adjectives based on distances from the query terms for document re-ranking. The third method calculates KLD scores of subjective adjectives for predefined query categories. In the fourth method, collocates, words co-occurring with query terms in the corpus, are used to construct the subjective lexicon automatically. The KLD scores of collocates are then calculated and used for document ranking. Four groups of experiments are conducted to evaluate the proposed methods on the TREC test collections. The results of the experiments are compared with the baseline systems to determine the effectiveness of using KLD in opinion retrieval. Further studies are recommended to explore more sophisticated approaches to identify subjectivity and promising techniques to extract opinions.

This paper examines cognitive repairs as they apply to the decision-making process used by venture capitalists, asking the question of “how could, or how do, cognitive repairs play a role in the decision-making process used by venture capitalists when evaluating a proposal for a new investment?” It begins by reviewing the well-documented concept of human decision-making biases and errors, and then shifts to an overview of the decision-making processes used by venture capitalists when evaluating a proposal for investment in a new venture. It then looks specifically at previous literature that identifies decision-making biases that venture capitalists fall prey to, and follows with reviewing the literature on cognitive repairs: organizational strategies that are used to compensate for or correct decision-making biases. Senior members of the venture capital industry were interviewed to empirically investigate this question, and it was found that while some strategies were in place to reduce human decision-making error, there was both room for and suggested evidence of a greater number of such errors. This leads to the suggestion that the increased use of cognitive repairs by venture capitalists could be beneficial, though this initial research is only of an exploratory format and warrants further investigation both more broadly and deeply.

Delivering the right information to the user is fundamental in information retrieval system. Many traditional information retrieval models assume word independence and view a document as bag-of-words, however getting the right information requires a deep understanding of the content of the document and the relationships that exist between words in the text. This study focuses on developing two new document ranking techniques, which are based on a lexical cohesive relationship of collocation. Collocation relationship is a semantic relationship that exists between words that co-occur in the same lexical environment. Two types of collocation relationship have been considered; collocation in the same grammatical structure (such as a sentence), and collocation in the same semantic structure where query terms occur in different sentences but they co-occur with the same words. In the first technique, we only considered the first type of collocation to calculate the document score; where the positional frequency of query terms co-occurrence have been used to identify collocation relationship between query terms and calculating query term’s weight. In the second technique, both types of collocation have been considered; where the co-occurrence frequency distribution within a predefined window has been used to determine query terms collocations and computing query term’s weight. Evaluation of the proposed techniques show performance gain in some of the collocations over the chosen baseline runs.

This paper examines the competitive dynamics in a standard-based industry through a historical examination of the U.S. home video industry. It analyzes how the Blu-ray technology wins the battle of the high definition DVD market over HD-DVD technology, by focusing on the aspects of the first-mover advantages, network effects. The analysis suggests that the success in the network-based industry partially support to traditional argument on first-mover advantages; they were important only to the point that the first mover takes advantages of the lead time to develop a network of complementary products. This study illustrates that building a network of complementary products and installed base should be the primary goal to succeed in the standard setting competition.

Archival data of unrestricted and restricted gift card transactions was compared with national level consumer spending data from both the U.S. and Canada to investigate the similarities and differences in purchase pattern. The objective for this comparison was to investigate the motivational power of unrestricted gift card compared to cash rewards, restricted gift card and other hedonic tangible incentive. Through results interpretation, the data supported the hypotheses that people perceive and use unrestricted gift card as a cash carrying medium rather than a tangible reward. A restricted gift card that is hedonic by design constrains its recipients to hedonic purchase and removes the guilt and eliminates the justification process. The results also suggested that the elimination of justification seems to be associated to not only the hedonic dimension of goods/services but also transaction size.

Communities of practice are groups of people who share a concern, a set of problems or a passion about a topic, and who deepen their knowledge and expertise in this area by interacting on an ongoing basis (Wenger et al, 2002). An understanding of why working, technical professionals participate in knowledge- based communities of practice can provide better opportunities to support individual and organizational knowledge management strategies. Online communities of practice were investigated at two global corporations: Xerox and IBM. At Xerox, Eureka is an internal network service designed to support knowledge sharing and problem solving by a community of practice for field service technicians. It allows the submission of problems from field service technicians and the retrieval of validated solutions for use and adaptation, by all members of the global Eureka community. At IBM Corporation, public network based communities of practice were investigated that focused on db2™ and Websphere™ software technology. Unlike the Xerox Eureka community of practice, knowledge contributions at IBM communities of practice are not validated prior to submission and access is open to public participation globally by IBM employees and by independent users of IBM software technology. The purpose of this case study research was to explore and to describe how and why participants became members of communities of practice – what influenced them to join and to participate. We collected survey data from participants in these communities, to examine the relationships among members’ expectations of purpose, their relationship to the community of practice, their attitudes toward information handling, the costs and benefits of membership, the size of the community of practice and the resulting participation behaviour in these knowledge-based communities of practice at Xerox Corporation and IBM Corporation. As one aspect of exploring user behaviour, we investigated the applicability of two theoretical frameworks for understanding user behaviour in these communities, based on propositions from normative and utility theory and from public goods critical mass theory. The research study provides a test for the explanatory power of public goods, utility and normative theories in a new area; namely, online knowledge-based communities of practice in workplace contexts. This analysis provided support for the applicability of utility theory and for some aspects of public goods-based theory/critical mass theory. The findings of the case study point out some differences in the two communities of practice. A majority of the IBM-based community members reported belonging to multiple communities (6-10) and using access to the community to form online social networks and to meet members outside the community at in-person meetings. They reported their participation as being self-directed and on an ad hoc basis. Most respondents were community members for less than 2 years. In contrast, a majority of Eureka members reported belonging only to the Eureka community and do not report forming online social networks in Eureka. Participation in Eureka is seamlessly integrated into prescribed, standard work practices of the company and supported by company management and with resources. Most respondents were community members for over 5 years. The analysis of members’ contributing behaviour in two online communities of practice reaffirms that the majority of members are passive participants with a core group of regular message contributors. Message composition is a careful and deliberate activity requiring communication discipline, time and effort. Members in both settings reported a strong desire to spend more time in their communities (and more time per visit). Communities of practice are dynamic complex entities that present not only a theoretical challenge but also a practical challenge. This study’s results point to the complexity of facilitating communities of practice: benefits dynamics and flow and permanence dynamics of membership can only be externally managed to a limited extent. The participants’ roles need to be conceptualized in ways that support different types of participation while at the same time highlighting the inherently cooperative nature of self-managed communities of practice.

One of the main challenges that investors in the Clean Development Mechanism (CDM) project face is the management of the volatility of the price of Certified Emission Reduction (CERs). Large scale CDM projects require a long-term investment with significant amount of costs, and this type of investment is often irreversible. Project investors should quantitatively assess the CER trigger price that justifies the initiation of a CDM investment. The traditional discounted cash flow valuation is unable to capture the option value associated with uncertain investment, and thus it tends to underestimate the trigger price which initiates the investment. Real options theory explicitly considers the option value of delayed investment and can provide a better measurement of the trigger price. This paper presents a theoretical model of the CDM investment project and derives the CER trigger prices that guide investment decisions by using historical market data. It develops a stochastic dynamic programming model for both the geometric Brownian motion process and the mean-reverting process. An analytical solution for the trigger price is derived for the former process, and the trigger price is numerically estimated for the latter. By considering various parameter values, it analyzes the effects of different market environments on the trigger price.

This thesis investigates the process of communication between a person who has in-depth and technical knowledge about certain items and a person who has very broad and non-technical knowledge. For example, a doctor has detailed knowledge about all types of diseases, whereas, an ordinary person only knows a few common type of them. People use categories to communicate; the language, which is used in communication, is categorical. In addition, knowledge can be expressed in categories, and the categories are formed based on the knowledge that the person has. If the person has a superficial knowledge about a specific subject, he then creates superficial categories; whereas, if he has in-depth knowledge, he creates detailed and technical categories. The communication process between a person with technical categories of knowledge and a person with non-technical categories can be presented by the way that they match their categories. Shared cognition is formed if a category exists or is formed that is completely understandable for both parties. Literature on communication studies have never focused on the way that people with categorical knowledge communicate; therefore, an exploratory study is designed to figure out the process of communication when people have categorical knowledge. The task that is used in this study simulates the situation that two persons with categorical knowledge are communicating. The results of this thesis introduce a new representation for the communication process between a technical and non-technical communicators and the way that shared cognition can be analyzed.

Storytelling is a powerful means of communication that has been employed by humankind from the early stages of development. As technology has advanced, the medium through which people tell stories has evolved from verbal, to writing, performing on stage, and more recently television, movies, and video games. A promising medium for the telling of stories in an in-person, one-on-one or one-to-many setting is a digital table—a large, horizontal multi-touch surface—that can provide quick access to visuals and narrative elements at the touch of one’s hands and fingers. In this work, I present the results of an exploratory study on storytellers’ interaction behaviours while working with digital tables, and its physical counterparts of sand and water. My results highlight some of the differences in these media that can both help and hinder a storyteller’s narrative process. I use these findings to present design implications for the design of applications for storytelling on digital multi-touch surfaces.

This investigation will use this ability in a different way. Studies have shown that a category can create a grade structure of prototypical items. We will take a graded structure generated by a category, and see if we can recreate the category based on presenting prototypical examples in a variety of ways. Five different sampling techniques will be used to determine which one is the best for category reconstruction. Since the items themselves have bits of information about the category, the number of samples presented will also be manipulated to determine if this is a factor in determining the category. The independent variables investigated were: sampling technique, and prompt conditions. In determining the effect of the independent variables on matching a category, the independent variables were also considered as mediating variables of each other. The method of opportunistic sampling was used for the surveys. The main participants were undergraduate 3rd year students taking a MSci 311 course at the University of Waterloo. Results indicate that there was no statistical significance. Fluctuations in significance levels indicate some random findings. Participants are not discriminating the samples or prompts which were given. This research is a contribution to this field because little research has been conducted in this area and implications are drawn for future research on the saliency of a category or attribute that can vary by context or knowledge