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