This dissertation examines a major policy change in the context of energy decision-making for shale gas development in the province of New Brunswick, Canada. After a long series of public engagement exercises aimed at regulating and promoting the safe development of shale gas resources in New Brunswick, the provincial government implemented a moratorium on hydraulic fracturing in 2014 and extended it indefinitely in 2016. The dissertation is interested in how policy-oriented learning may have influenced this policy change from both an empirical and a theoretical perspective. Theoretically, in line with recent scholarship on policy learning, this study trains its sites on the nature of policy learning and how it may influence change. To this end, the dissertation is grounded in the Advocacy Coalition Framework (ACF), a theoretical approach with (i) clearly defined mechanisms of learning, and (ii) significant application to resource development and to case studies of resource development in jurisdictions across North America and globally. The study builds on the ACF by proposing a conception of learning drawing on post-positivist literature. The study argues that learning is too narrowly focused on policy elites in the ACF and should be expanded to consider the role of non-traditional actors. The analysis questions the notion that learning can be isolated to rational and technical understandings amongst policy elites, and aims to integrate interactive knowledge into the analysis as a fundamental component of learning. The research aims to contextualize learning and understand the factors that shape policy learning and policy change. The dissertation focuses on the role of three factors - public engagement, uncertainty and trust - in shaping policy actors' learning. Empirically, the study examines the case of New Brunswick between 2007 and 2017. The province undertook multiple public engagement exercises regarding shale gas development in the context of unknown risks and uncertainty associated with the practice of hydraulic fracturing, an emerging technology that enabled the production of shale gas on a large scale. Two major coalitions emerged that advocated for and against shale development in the province, with the dominant pro-development coalition asserting that shale gas could proceed safely through stringent regulation. Through documentary analysis, interviews and a media analysis, the research reveals that interactive knowledge was a key component of how people learned in the case. The anti-shale coalition in New Brunswick brought its lived experience - notably its lack of trust in public authorities to successfully regulate fracking - to bear on decision-making, and was able to undermine and question the pro-development coalition's position that the risks associated with hydraulic fracturing could be managed. The anti-shale coalition mobilized this knowledge through the government's public engagement exercises and successfully contested the dominant coalition's beliefs. Fundamentally, the study demonstrates that public engagement, uncertainty and trust are three key factors that can shape policy learning and change.