Management Science and Engineering

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This is the collection for the University of Waterloo's Department of Management Science and Engineering.

Research outputs are organized by type (eg. Master Thesis, Article, Conference Paper).

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Now showing 1 - 4 of 4

Effects of Incentives on Group Problem Solving Processes and Paths
(University of Waterloo, 2020-08-17) Grinberg, Arielle; Duimering, P. Robert
Incentives have been known to affect group performance when solving complex problems. Groups that are given individual incentives for solving problems are able to solve problems quicker, and with less errors compared to those that are given group incentives. However, much is unknown about the underlying cognitive and social factors that influence problem solving in conjunction with incentives. Research has neglected to investigate the process by which groups move from an initial problem state to the solution state. There is a heavy involvement of coordination between members, even between a heterogeneous group where members have their own individual goals. Groups must first agree upon a solution, or goal state, and members must solve their own sub-goals in conjunction with one another to ensure there is no conflict or overlap. This research explores the different routes that groups with varying incentive structures take when solving a complex problem. A previous study was analyzed where groups were given four cards with pictorial items and each member was asked to collect four of a kind. The study revealed that the most complex condition, detour and restructuring, showed the largest differences between incentive groups. In this condition participants could fall into blind alley categories, and must detour around these false sets in order to reach the correct solution. The solution also consisted of three similar pictorial items and one superordinate item, requiring participants to cognitively restructure their perception of the category sets. Thematic coding was done on transcripts of the experimental videos, and differences between groups were analyzed. Additional analysis was also conducted on the way each group organized their solution paths by investigating the order of category labels that groups would produce. Results showed that groups given individual incentives had much more organized paths, were less willing to explore the problem space, and had a better understanding of problem structure compared to groups given a group incentive. Individual incentive groups were also more likely to move directly towards the solution, and spend less time creating category labels for incorrect category solutions. Overall, these results contribute to the problem solving research field by establishing that the behaviours and characteristics of groups solving complex problem vary not only on internal factors, such as personality type and expertise, but also based on external factors, such as incentive types.
The structuring of ambiguous stimuli in human communication
(University of Waterloo, 2016-05-18) Pimenta, Geovania; Duimering, P. Robert
Abstract Information theory (Shannon, 1948) and relative similarity (Rosch and Mervis, 1975) are used to investigate the problem of how people communicate about ambiguous, unstructured stimuli. Specifically, the following one-way communication setting is considered: given a set of ambiguous items available to both a sender and a receiver, the sender uses messages to describe one of the items from the set, such that the receiver is able to identify this target item correctly. It is argued that information reduces uncertainty in ambiguous communication settings through the development of structure, which is conceptualized in terms of a system of categories. During the communication process, distinguishing an item from a set of other items involves clustering items into subsets; that is, grouping items together that are similar to one another and leaving out items that are dissimilar. It is proposed that relative similarity is the cognitive mechanism involved in the development of those categories. It is further proposed that perceptions of relative similarity are made with respect to one attribute. People take advantage of the perceived structure of the ambiguous stimulus and form categories in a goal-directed manner, focusing on whatever attribute best enables them to distinguish the target item from the others (Barsalou, 1983). Each time one attribute is used in communication to refer to a cluster or subset of items, uncertainty is reduced. Furthermore, it is postulated that when people have the choice of one attribute from multiple possible attributes to communicate about unstructured stimuli, two categorization logics operate to reduce uncertainty. Hypothesis 1 predicts that people maximize distinctiveness by choosing the attribute that allows for a larger gap (i.e., greater dissimilarity) between the subset containing the target item and the subset of remaining items. Hypothesis 2 predicts that people maximize information gain by choosing the attribute that allows for the smaller subset containing the target item. The theoretical framework is built upon illustrative examples. Three experiments were conducted to investigate the cognitive mechanisms that people use to identify and describe a specific ambiguous item from among a set of ambiguous items during communication. Participants took the role of either sender or receiver in a one-way communication situation. In the role of sender they ranked a set of descriptions/attributes based on the degree to which they thought the descriptions would enable an imagined receiver to identify a specific target item from a set of ambiguous items. As receiver, they were given specific descriptions/attributes from an imagined sender, and ranked a set of ambiguous items based on which of the items they thought the sender was referring to. Experiments 1 and 2 used two different kinds of unstructured stimuli; experiment 3 utilized a structured way of manipulating unstructured/ambiguous stimulus. The results of experiments 1 and 2 were consistent with hypotheses 1 and 2. There were strong consistency between the two different stimuli and, therefore, strong evidence for generalizability of the observed effects. The results of experiment 3 gave inconsistent support for the hypotheses. The theoretical framework, the design of the experiments, and the results are discussed.
Trade-offs in Design: A Theory Building Qualitative Study on the Role of Problem Formulation and Framing in Resolving Trade-offs in Design
(University of Waterloo, 2021-08-12) Nickel, Jordan; Hurst, Ada; Duimering, P. Robert
Design projects are complex problem-solving endeavors that can involve many goals that are often conflicting. These trade-offs between goals have been primarily studied through the lens of optimization, attempting to create the best possible solution under the constraints of the conflicting goals. However, the broader design literature indicates that design problems are characterized by being ill-defined. As a result, designers need to interpret, formulate, and frame the problem they are attempting to solve, and they must do this without a well-defined set of constraints and requirements. To this end, designers use solutions concepts to explore their problem, and this causes the design problem and solution to coevolve. This research explores the ways that designers formulate and frame trade-offs, how they can manipulate their formulation and framings of the problem to resolve trade-offs, and the aspects of their design situations that influence how challenging these reformulation and reframing processes are. A theoretical framework was derived using set theory to model and describe a designer’s formulation and framing of their problem and solution, which is labeled the design space. The framework also utilizes the concept of Pareto optimality to formally define design trade-offs within a design space. An intensionally defined set of possible manipulations to this design space was identified using this theoretical framework, which informs how those manipulations can be used to resolve trade-offs. This framework also models how a designer’s perceptions and expectations of their design spaces can differ from the real performance of their solutions due to inherent cognitive limitations, information availability, and biases. A semi-structured interview approach was used to explore how practicing designers framed and formulated their initial trade-off situation, and how they manipulated those aspects in their resolution of the trade-off, if at all. Additionally, an echo interview process was used to investigate what influences the designers perceived as affecting how challenging their trade-off situations were to resolve. Seven different approaches to resolving trade-offs were identified in the dataset through a case study analysis, which were classified by how they manipulated the design space. Four of these approaches actively manipulated the designer’s perceived design space to resolve the trade-off, two altering the boundaries of the space and two altering the parameters that comprised the space. These manipulations allowed the designers to restructure their design space and the trade-offs therein to make them easier to resolve. In some of the cases studied, the manipulations also allowed the derivation of solutions that dominated the Pareto frontier of the original design space. In addition to the case study analysis, a thematic analysis was used to identify the aspects of the situation that made manipulating design spaces and resolving trade-offs either easier or more challenging. From this nine codes were identified, sorted into three themes. The three themes were how the design space was initially structured, how well a designer’s expectations aligned with the real outcomes of decisions, and how previous decisions impacted the options available to a designer. The results showed that designers can and do manipulate their problem formulation and framing to resolve trade-offs. This indicates that optimization approaches in design need to account for the dynamic structure of the problem, and that designers should be aware that results of an optimization approach reflect the structure they impose on their design problems. Overall, this research contributes to understanding how designers perceive and frame trade-offs, what tools they have at their disposal to resolve them, and what challenges they encounter while resolving them.
Using a Credibility Classifier to Improve Health-Related Information Retrieval
(University of Waterloo, 2020-08-19) Beylunioglu, Fuat Can; Smucker, Mark; Duimering, P. Robert
In this thesis, we address improving the credibility and correctness of information retrieved by search engines in health-related searches. Health misinformation presented in the search engine results pages (SERPs) is a challenging problem to search engines whose successes have been measured with the number of URLs in the SERPs relevant to the user's query. However, research shows that relevant but inaccurate information can lead to wrong decisions, which is a challenge to the current search engines. Although existing studies have proposed different ways to help to make better health decisions, there is not much done in the information retrieval context. In our study, we proposed algorithmic methods to improve correct and credible information presented in the results pages. The algorithms are motivated by the hypothesis that credibility of a document correlates with its correctness. Therefore, we trained classifiers to predict the credibility of documents retrieved by a search engine and adjust their ranks based on the credibility and spaminess scores. To test the performances of the algorithms, we have conducted an experiment as a part of our participation in TREC Decision Track 2019. As we show in this study, we can significantly improve the baseline BM25 algorithm in credibility and correctness tasks. We also present an analysis of the credibility and correctness judgments produced for the track to give insight into the distribution of credibility and correct documents retrieved in health-related tasks. Our analysis suggests that credibility can help to reach accurate information when the underlying treatment is ineffective, but there is a limit to its contribution to users' search experience.

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Browsing Management Science and Engineering by Author "Duimering, P. Robert"