The original formulation was deceptively simple. A threshold concept, Meyer and Land argued, is likely to be transformative, probably irreversible, integrative, possibly bounded, and potentially troublesome. Their now-famous example involved a cup of tea cooling after milk is added. At an everyday level, a learner might say cold milk makes hot tea cooler. Within a disciplinary way of thinking, however, the same event opens onto heat transfer, temperature difference, and thermal equilibrium. The learner must abandon the idea of hotness and coldness as isolated properties and grasp cooling as a relational process. That perceptual shift is not merely another fact acquired; it changes how the learner interprets the physical world. Crossing such a portal, the authors argued, leads to a transformed way of understanding without which the learner cannot progress, and mastery is both intellectually and personally transformational, altering identity itself.

Subsequent scholarship expanded the list of characteristics to eight, adding discourse, reconstitution, and liminality, the unstable betwixt-and-between state borrowed from anthropologists Van Gennep and Turner in which learners oscillate between old and emerging understandings. That expansion, however, became a target. Critics such as David Rowbottom argued that threshold concepts lack clearly stated necessary and sufficient criteria, while others questioned whether all five original criteria must be present each time a threshold is identified. In medical education, Brown, Whybrow, and Finn went further, describing a floating signifier problem in which definitional ambiguity lets threshold concepts mean different things in different contexts, and asking whether the field should simply close the door on the framework altogether.

The methodological critiques cut deeper still. Studies vary enormously in who identifies threshold concepts, whether students, academics, or practitioners; in the methods used; and in how agreement is reached. Without explicit criteria, researchers may be characterising entirely different things as thresholds: a difficult topic, a core disciplinary idea, a curricular bottleneck, or a genuinely transformative concept. A third line of critique raised political concerns, arguing that naming particular concepts as thresholds privileges certain disciplinary worldviews, presents disciplines as more coherent than they are, and risks treating identity formation as primarily cognitive rather than social. Naming something a threshold concept, these critics note, is never a neutral act; it determines what counts as disciplinary knowledge and whose expertise is legitimised.

The new analysis does not dismiss these critiques but reframes them. Drawing on Sarah Hill’s work in prosthetics education, the authors emphasise that troublesome knowledge and threshold concepts are not synonymous. Many concepts are simply hard to learn, such as biomechanical calculations or anatomical lists, without producing the integration and ontological transformation necessary for threshold status. A true threshold concept requires contextualised experience and associated memories that bind procedural and disciplinary concepts together, ultimately shifting the learner’s worldview. Content can be difficult without being a threshold; what distinguishes a threshold is that it changes the learner’s sense of self. Davies and Mangan’s work in economics reinforces this structural view: genuine mastery occurs only when disciplinary concepts, the theoretical lenses of a field, are integrated with procedural concepts, the methods through which the discipline constructs arguments.

The authors also challenge the binary view of threshold crossing, in which a student either gets it or does not. Calduch and Rattray’s concept of postliminal variation, the variation in the point and state of exit into a new conceptual space, suggests that different, valid transformations can arise from the same threshold concept. Far from being a defect, this variability is evidence that thresholds are living sites of knowledge creation rather than fixed checkpoints. In a vivid metaphor, the authors compare threshold concept characteristics to a cake recipe: the ingredients matter, but the proportions vary by discipline, some cakes contain no fat at all, and the threshold concept is the baked outcome of interacting characteristics, not any single ingredient. Evaluating a threshold concept on the basis of one characteristic alone, they argue, leaves a bad taste.

The analysis’s most novel contribution is its positioning of uncertainty tolerance as the central analytic lens for the field. Uncertainty tolerance describes how individuals respond to unknowns across cognitive, emotional, and behavioural domains, whether the source is complexity, ambiguity, or probability. Land himself framed threshold concepts as a pedagogy of uncertainty, and the new paper argues that this construct offers a robust mechanism for distinguishing true, identity-shaping thresholds from merely troublesome knowledge. Learners can respond adaptively to the uncertainty of liminality, with curiosity and confidence, or maladaptively, through disengagement, denial, or endless certainty-seeking without forward progress. In high-stakes contexts such as education, research suggests most people will feel emotionally distressed regardless of their behavioural response, which makes the educator’s role in scaffolding that distress critical.

This reframing carries concrete implications for curriculum design and assessment. Rather than eliminating thresholds or smoothing the learner’s journey, educators should strategically identify these junctures and scaffold learner resilience, timing exposure to discipline-related thresholds and supporting adaptive responses through questioning preconceptions, transferring knowledge across contexts, presenting multiple points of view, and working through purpose-built grey cases. Assessment, meanwhile, should not simply ask whether learners acquired content but should generate evidence of how learners reason, act, and position themselves when existing assumptions no longer provide certainty: reflective writing, concept maps, portfolios, and narrative accounts of uncertainty can reveal uncertainty responses, conceptual integration, and identity-level change. The authors also stress that identification should not rest with instructors alone; learners’ accounts of their own discomfort in the liminal space are essential evidence, guarding against the framework becoming an unexamined mechanism for reproducing dominant professional norms.

The paper acknowledges its own limits: it is conceptual rather than empirical, and the link between threshold concepts and uncertainty tolerance requires investigation across disciplines, learner groups, and institutional contexts. But its closing argument is deliberately recursive. The framework of threshold concepts, the authors conclude, is itself a threshold concept: troublesome, requiring educators to tolerate ambiguity; liminal, forcing a renegotiation of teachers’ own identities; and, once understood not as a rigid rulebook but as a lens for complexity, irreversibly transformative in how one experiences education. To master the framework is to accept that learning in higher education is not a linear transfer of knowledge but a complex, uncertain, and profoundly human struggle, and that the goal of education is not to remove that struggle but to equip learners to navigate it.

Subject of Research: The theoretical coherence of the threshold concepts framework in higher education and its integration with uncertainty tolerance

Article Title: Threshold concepts: Tensions and truths

Article References: Threshold concepts: Tensions and truths. (n.d.). https://doi.org/10.1007/s10734-026-01752-9

Image Credits: AI Generated

DOI: 10.1007/s10734-026-01752-9

Keywords: threshold concepts, higher education, uncertainty tolerance, liminality, troublesome knowledge, curriculum design, transformative learning, professional identity, pedagogy, assessment, educational theory, Threshold

The study, led by Sandy Rao of Wilfrid Laurier University together with Aman Ahluwalia-Cameron, Nicola Hodgson, Andreas Vavvos and Susan McGuire, draws on an empirical and reflective analysis of the first cohort of the Applied Critical Realist Fellowship, an international higher education initiative designed to support researchers who want to use critical realism in their work. Rather than treating the fellowship as a conventional curriculum, the authors treat it as a lived learning environment in which the perennial pedagogical challenge of making foundational theory accessible and meaningful can be observed in real time. Their guiding question is deceptively simple: what actually happens when people who are not philosophers try to learn a demanding philosophy together?

To answer it, the researchers turned to a concept borrowed from science and technology studies: metaphor-work, developed by Cowan and Rault in 2022. Metaphor-work describes the deliberate, collaborative use of metaphors, images and analogies as resources for reasoning, not merely as decorative simplifications. Within the fellowship, a subgroup of participants formed specifically to engage with critical realist concepts through this kind of figurative labour. Instead of parsing Bhaskar’s original texts line by line in isolation, members generated and tested metaphors for ontological depth, stratification, causation and emergence, negotiating which images captured the theory faithfully and which distorted it. The metaphor became a shared object of thought, something the group could point at, refine and argue with.

The analytical payoff of the study lies in what this process revealed about the nature of learning itself. The authors conclude that learning critical realism is not a purely cognitive achievement, a matter of grasping propositions and reproducing definitions. It is simultaneously cognitive, affective, relational and structurally mediated. Cognitively, metaphors allowed participants to hold abstract claims about an intransient reality and its emergent social strata in working memory long enough to interrogate them. Affectively, the work surfaced anxiety, excitement and the vulnerability inherent in admitting confusion about foundational ideas. Relationally, the group’s dialogue and mutual care provided the safety needed for that vulnerability. Structurally, differences in disciplinary background, institutional resources and access to philosophical mentoring shaped who found the theory approachable and who struggled.

This multidimensional account challenges a persistent assumption in research training: that theory is best transmitted through authoritative exposition followed by individual application. The fellowship’s experience suggests the opposite. When formal instruction is unavailable or uneven, learners can construct their own scaffolding collectively, and metaphor is one of the most powerful materials for that construction. Metaphors operate as what the authors, following earlier literature on threshold concepts, might recognise as portals into troublesome knowledge. Concepts such as emergence or the difference between the transitive and intransitive dimensions of science are precisely the kinds of ideas that Meyer and Land described as threshold concepts: ideas that transform how learners perceive a field, often causing disorientation before yielding genuine understanding.

The technical heart of the study is its treatment of metaphor as epistemically productive rather than epistemically suspect. Within critical realism there has long been a debate about the role of figurative language, reaching back to Paul Lewis’s 1996 analysis of metaphor and critical realism in the Review of Social Economy. Metaphors can mislead, reifying one stratum of reality into another or smuggling in assumptions the theory rejects. The fellowship subgroup addressed this risk by treating metaphors as provisional and revisable. A metaphor for generative mechanisms, for example, would be proposed, stress-tested against the text, challenged for the ontological commitments it implied, and then refined or discarded. This iterative negotiation meant the group was doing philosophy, not bypassing it. The metaphor-work functioned as philosophical reasoning conducted through images rather than despite them.

The findings have immediate practical implications for graduate education and faculty development. Doctoral students attempting critical realist dissertations frequently report isolation, a problem documented in earlier work by Hastings, Davenport and Sheppard on the loneliness of the long-distance critical realist student and their later account of thinking like a critical realist. The new study suggests that structured collective metaphor-work could be institutionalised within writing groups, research training programmes and interdisciplinary research centres as a deliberate pedagogical practice. Conveners need not be critical realist experts; they need to facilitate the disciplined generation, comparison and critique of analogies, creating conditions of dialogue, reflexivity and care in which difficult concepts become discussable.

The study also speaks to a structural inequity in global higher education. Access to philosophers of science, to Departments capable of teaching metatheory, and to the time required for deep theoretical reading is unevenly distributed across institutions and regions, particularly between the global North and South. Initiatives such as the Applied Critical Realist Fellowship, and the educational development scholarship of researchers like Chris Bouhey and Sioux McKenna, highlight that the capacity to teach theory is itself a resource requiring cultivation. By theorising metaphor-work as a collective pedagogical practice that does not depend on expensive philosophical infrastructure, the authors offer a scalable model for theory-informed research training in contexts where such infrastructure is thin. The practice is low-cost, transferable across disciplines, and compatible with existing forms of collaborative learning.

Crucially, the authors frame the learning they observed as an emotionally and relationally supported process rather than a cold transfer of content. Participants’ affective responses were not noise interfering with cognition; they were constitutive of it. The care members showed one another, the patience with repeated confusion, and the willingness to revisit failed metaphors created what the analysis describes as conditions for reflexivity, the hallmark disposition of critical realist inquiry itself. In this sense the pedagogy mirrored the philosophy: just as critical realism insists that knowledge production is a socially situated, stratified and fallible process, the fellowship’s learning was socially situated, layered across cognitive and emotional registers, and openly revisable. The medium became a lesson in the message.

The study’s contribution is therefore twofold. Empirically, it documents how a specific international cohort grappled with one of the most philosophically demanding frameworks in contemporary research, providing rare granular insight into the mechanics of metatheoretical learning. Theoretically, it elevates metaphor-work from a scattered set of classroom tricks into a named, analysable collective pedagogical practice with implications for interdisciplinary learning, graduate supervision and professional development across the applied sciences. For the growing community of researchers in social work, health research, management, psychology and environmental studies who cite critical realism as their framework but struggle to explain it to colleagues and students, the message is encouraging: the way into difficult theory may not be through solitary philosophical endurance, but through the shared, careful, sometimes playful labour of finding the right words and images together, and then, crucially, finding out together where those words and images break down.

Subject of Research: Collective metaphor-based pedagogy for learning critical realism in higher education

Article Title: Learning critical realism in higher education: metaphor-work as collective pedagogical practice

Article References: Rao, S., Ahluwalia-Cameron, A., Hodgson, N., Vavvos, A., & McGuire, S. (2026). Learning critical realism in higher education: metaphor-work as collective pedagogical practice. Higher Education. https://doi.org/10.1007/s10734-026-01777-0

Image Credits: AI Generated

DOI: 10.1007/s10734-026-01777-0

Keywords: critical realism, metaphor-work, pedagogy, higher education, collective inquiry, threshold concepts, interdisciplinary learning, graduate education, faculty development, applied philosophy, Learning, critical