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Recent Submissions

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    Use of Large Language Models (LLMs) in Qualitative Analysis: Evaluating LLMs as Assistive Coding Agents
    (University of Waterloo, 2026-02-19) Neeb, Mikayla
    Introduction: Large language models (LLMs) are increasingly used to support qualitative research, yet robust methods to evaluate the quality of LLM-generated codes remain underdeveloped. Existing approaches often rely on comparisons to human ground truth or custom evaluative methods, limiting cross-study comparisons. This study examines whether LLMs can function as assistive qualitative coding agents and introduces the CReDS framework as a structured approach to evaluating LLM-generated codes without the need for a comparative codebase. Methods: Two social media datasets were employed as validation sets to systematically develop and test approaches for evaluating LLM-generated inductive codes. Codes were generated using GPT-4o-mini and assessed through an iterative evaluation process. Initial assessment relied on conventional quantitative similarity metrics (e.g., cosine similarity); however, limitations in capturing qualitative distinctions prompted the incorporation of structured human evaluation. This process led to the development of the CReDS framework, comprising Consistency, Relevance, Distinction and Specificity, as a more comprehensive evaluative method. Targeted exploratory analyses further examined evaluative performance under specific conditions, further investigating the evaluative methods explored in this study. Results: LLM-generated codes aligned closely with human codes across both datasets, with overall semantic match rates ranging from 74-83%. At the text level, 65-95% of inputs had at least one LLM-generated code judged appropriate by human reviewers. CReDS scores revealed strong alignment to human-generated codes, with strong overlap across all dimensions. However, LLM-generated codes showed reduced specificity, and the CReDS framework observed conservative scoring behaviour. Despite these limitations, CReDS effectively surfaced systematic strengths and weaknesses in LLM outputs. Conclusions: These findings indicate that LLMs can reliably support early state qualitative coding when used as assistive tools under human oversight. The CReDS framework offers a transparent and scalable method for evaluating LLM-generated codes that align with qualitative principles while supporting iterative model development. This study contributes to a measurable and scalable platform for responsible human-AI collaboration in qualitative analysis and highlights directions for refining evaluation frameworks in future work.
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    A Child Friendly City: Redesigning Urban Spaces for Child Mobility and Play
    (University of Waterloo, 2026-02-18) Villasmil Wilhelm, Sofia
    Cities are rarely designed with children’s wants and needs in mind. Instead, they are shaped in ways that limit children’s opportunities for free play and independent mobility. These experiences are fundamental to children’s development and wellbeing, and their absence highlights a critical gap in contemporary urban design. This thesis investigates how such conditions shape and contribute to a child-friendly city and explores how urban environments can be redesigned to better support them. The research combines a literature review outlining the qualities that define a child friendly city, alongside an examination of the factors currently preventing cities from being considered child-friendly. It also includes a participatory workshop conducted with children to gain first-hand insight into their lived experiences, as well as a precedent analysis of places that are beginning to implement child-friendly interventions. Through this combined approach, the research identifies key spatial factors influencing children’s free play and independent mobility, including supported risk, flexibility, agency, and the inclusion of children’s voices. It also examines conditions and practices that should be avoided in child friendly urban design. These insights are translated into a set of adaptable design guidelines that prioritize children’s free play and independent mobility. Their application is demonstrated through three design proposals across sites of varying urban densities in Toronto, a city chosen for its wide range of urban conditions and openness to cultural and civic improvement projects. By positioning free play and independent mobility as central considerations in urban design, this thesis offers a practical framework for those seeking to create thriving and inclusive child-friendly cities.
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    Perceived Restorativeness and Restorative Outcomes: A Comparative Study of Diverse Environments in Urban and Natural Settings
    (University of Waterloo, 2026-02-18) Grant, Emily
    Natural environments are generally considered more restorative than urban ones, with various elements contributing to their restorative potential. This research investigates restoration in urban and natural environments using virtual reality and field studies. In particular, I examined urban and natural environments with both high and low restorative potential. Additionally, this research explores if participants can effectively evaluate an environment’s restorativeness based solely on the environment’s visual aspects. Across studies, restoration was assessed using subjective and objective measures of stress, attention, and affect. Results demonstrated that the natural environments did not consistently outperform the urban environments on restorative outcomes. Indeed, there were some indications that urban environments could also be restorative. Finally, participants’ predictions of restorative potential did not align with the restorative measures, indicating a gap between perceived restorative potential and actual restorative outcomes. Overall, the findings indicate that environmental restorativeness is complex, and not all urban or natural environments offer the same level of restoration. Further research is needed to understand the specific elements that contribute to an environment’s restorative potential.
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    Implications of a changing climate in coastal Labrador for caribou and their forage
    (University of Waterloo, 2026-02-17) Lauriault, Patrick
    The majority of Labrador’s coastal lands are below the 60th latitudinal parallel. Even so, the cold Labrador Sea currents, late-lasting sea ice, and frequent high winds, these coastal ecosystems often resemble Arctic and Subarctic ecosystems that are further north. Historically, these landscapes exhibited stunted shrub growth, but as the climate changes, the shrinking sea ice season and the cooling effects of coastal sea ice on nearby landscapes begin to subside, shrubs are now overtaking tundra vegetation communities. These shrubs threaten ground lichen communities in coastal regions. Understanding changes in vegetation allows us to predict changes in the forage available to caribou, a culturally and ecologically significant species in Labrador and other northern regions. Caribou tend to rely heavily on lichen in the wintertime to meet their dietary needs. In this dissertation, I addressed three main research questions: 1) How much lichen forage do caribou need to satisfy their energetic needs over winter? 2) With the state of ground lichen availability at three Labrador sites, what caribou density can be sustainably achieved at each location? 3) With climate change increasing coastal fog, how will lichen productivity respond to fog as a source of hydration? I used a time-series simulation to estimate caribou energetics over winter. After the simulation results, I assessed the state of ground lichen at three sites in coastal Labrador. The combined results are used to determine a sustainable caribou density at each location based on available winter forage. The caribou energetics simulation results showed that the average caribou must eat 1330 kg of lichen over the winter to avoid weight loss. The ground lichen estimates in open tundra at each of the three sites were 0.66 kg/m2 in Pinware (caribou free site), 0.1 kg/m2 in Cartwright (Mealy Mountain caribou) and 0.04 kg/m2 in Nain (George River caribou herd). With current lichen biomass estimates and an assumed 5% annual growth rate, I was able to derive sustainable caribou densities at each of the three sites (Pinware: 24 caribou/km², Cartwright: three caribou/km², Nain: one caribou/km²). I also studied how lichen productivity may be impacted by increased fog-based precipitation. Although lichens cannot compete vertically with shrubs, they may respond to climate change by becoming more productive when using fog water to increase growth in the growing season. Lichens readily use non-rainfall sources such as fog for their metabolism. Using a simulation model for lichen metabolism, I found that fog can encourage productivity in lichens, with my model showing a carbon uptake of 20 g on a 1 m2 ground lichen mat over four months from only observed fog events. Other promising findings from this study show that fog events happen much more frequently in the morning, hydrating the lichens before peak solar radiation. That fog alone will not block enough sunlight to achieve net photosynthesis. However, some troubling findings are that warmer months result in lower lichen productivity due to fog, as respiration begins to outpace photosynthesis at warmer temperatures. Fog water deposition is likely to increase in these environments, potentially altering lichen productivity in the north. Bottom-up constraints to caribou herds, such as a lack of forage, are essential to identify. Considering other threats caribou face can help herd managers and Indigenous people, who rely on caribou for a food supply, determine when intervention is required in a changing northern environment.
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    Fracture Characterization and Damage Accumulation Modelling of DP1180 Steel under Proportional and Non-Proportional Loading
    (University of Waterloo, 2026-02-17) Jeyranpourkhameneh, Farinaz
    Lightweighting remains a primary objective in the automotive industry, driven by the need to reduce fuel consumption and greenhouse gas emissions while meeting stringent crashworthiness standards. Advanced High Strength Steels (AHSS), such as Dual Phase 1180 (DP1180), have gained prominence due to their excellent strength-to-weight ratio. However, their complex fracture behavior under multiaxial and non-proportional loading conditions presents challenges for accurate failure prediction in structural simulations. This thesis aims to address these challenges through a systematic experimental investigation and modelling framework tailored to the fracture and damage response of DP1180 steel. The first phase of this work investigates the influence of gauge length on fracture strain in shear-dominated specimens. Conventional Digital Image Correlation (DIC) techniques were refined to enhance local strain measurement accuracy, focusing on strain localization in the shear zone. A series of tests were performed using butterfly shear specimens with varying gauge lengths to assess the lengthscale sensitivity of fracture strain. The results confirmed a strong dependence of measured fracture strain on the gauge geometry, reinforcing the need for standardized specimen design and DIC post-processing protocols. An optimized experimental configuration and robust DIC-based post-processing strategy were established to ensure consistent strain measurements for subsequent studies. The second component focuses on fracture under proportional loading conditions using uniaxial tension tests. Multiple specimen geometries were employed, including standard dogbone and notched samples, as well as conical hole expansion tests, to evaluate the fracture behavior of DP1180 under various constraints. Since fracture initiation under uniaxial tension is complicated by post-necking deformation, post-mortem surface strain analysis was performed to estimate local fracture strains. The study provided a reliable set of fracture strains for proportional loading conditions, allowing for direct comparison between different geometries and stress states. These results form the baseline for calibration and validation of fracture models under simple loading histories. The third phase of the work extends the investigation to combined loading paths involving simple shear and uniaxial tension. This approach enabled the evaluation of fracture behavior under intermediate stress states between pure shear and uniaxial tension. The resulting force-displacement responses and post-mortem strain measurements were used to validate the predictive capability of an existing phenomenological fracture model without necessitating re-calibration. The observed agreement between simulation and experiment under these combined stress states provides a robust validation of the model and highlights the versatility of the butterfly test methodology. To further extend the applicability of the framework, a novel experimental approach was developed to characterize fracture under non-proportional (bi-linear) loading paths. In this methodology, specimens were subjected to controlled proportional loading, after which miniature fracture specimens were extracted along different orientations and stress states. These samples were subsequently tested to failure, capturing the influence of pre-straining on fracture response. The collected data enabled an assessment of existing damage accumulation models under realistic forming conditions. Comparison with model predictions revealed that strain path changes significantly affect fracture strain evolution, especially for loading sequences that cross between tension- and shear-dominated states. These findings demonstrate the limitations of path-independent fracture criteria and underscore the importance of incorporating load history effects into damage modelling strategies. Overall, this thesis presents a comprehensive experimental framework for fracture characterization of AHSS under a wide range of loading conditions. The key contributions include: (1) development of a reliable shear fracture testing methodology that quantifies gauge-length sensitivity in DIC-based strain measurements, demonstrating variations in measured fracture strain depending on the selected length scale, (2) resolution of fracture strain identification under uniaxial tension through the combined use of multiple specimen geometries and post-mortem surface strain analysis, enabling the construction of a consistent proportional fracture dataset across a range of stress triaxialities, (3) validation of a phenomenological fracture model under combined shear–tension loading paths without re-calibration, showing good agreement between experimental observations and numerical predictions across intermediate stress states; and (4) development and application of a two-stage experimental methodology for evaluating fracture under non-proportional loading histories, providing a systematic assessment of path-dependent damage accumulation. Experimental results demonstrated that non-proportional loading generally leads to reduced fracture strains compared to monotonic proportional loading, with pronounced deviations governed by strain-path sequence and material anisotropy. Evaluation of the Generalized Incremental Stress State–Dependent Damage Model (GISSMO) showed that a damage exponent of 𝑛 = 2 provided the most consistent agreement with experimentally measured fracture strains across the investigated non-proportional loading conditions. Based on experimental repeatability and strain-field reliability, a hierarchy of confidence in the non-proportional fracture data was established, with v-bending tests exhibiting the highest confidence, followed by mini-biaxial, hole expansion, and shear tests. Collectively, these findings advance the understanding of path-dependent fracture and damage accumulation in DP1180 steel and provide experimentally validated guidance for improving the fidelity of forming and crashworthiness simulations involving advanced high-strength steels.