Evidence rarely arrives already dressed as evidence. It arrives first as a disturbance — a recurring behaviour in a public space, a pattern of heat exposure, an anomaly in platform visibility, a gap in an archive nobody had noticed until someone went looking — and only later, if it survives scrutiny, does it acquire the calmer name we give it in a finished paper. Peirce, Popper, Kuhn, Polanyi and Feyerabend mark distinct moments in the longer argument about how that survival happens, and it is worth resisting the temptation to flatten them into a single tidy lineage — each disturbs a different comfort. Peirce treats inquiry as correction under uncertainty rather than as the accumulation of settled fact: belief stays provisional, and inference moves through abduction, deduction and induction in a continuous, corrigible loop. Abduction — the generation of a plausible explanatory hypothesis from a surprising observation — matters especially for architecture, environmental psychology, urban research and media studies, fields in which observation regularly precedes any stable causal account. The task of inquiry is to formulate an explanation that can be tested, not to convert the anomaly prematurely into support for a theory one already favours.
Popper's enduring importance lies in the demand that scientific statements expose themselves to the possibility of their own failure. Falsifiability is too often flattened into a procedural slogan, yet its deeper contribution is at once ethical and architectural: a claim ought to be built so that counter-evidence has somewhere to enter it. Where the route from assertion to evidence has been broken, obscured or deliberately closed off, a claim can no longer be treated as epistemically secure — verification is not identical with truth, but in its absence claims come to rest on authority rather than on contestability, which is a considerably weaker foundation than it appears from the inside. Kuhn, in turn, destabilises the very assumption that evidence can be read independently of disciplinary history. Paradigms organise exemplars, instruments, standards and legitimate questions, and they determine — often invisibly — what researchers notice and how anomalies get classified in the first place. Normal science earns its productivity by stabilising a field long enough for cumulative work to accumulate; that same stability breeds a characteristic blindness, in which evidence failing to fit the dominant grammar can look merely irrelevant rather than revolutionary. A single observation, as Kuhn's later readers keep discovering for themselves, can sustain more than one interpretation, and the background assumptions a claim requires in order to cohere are rarely stated by the people who most depend on them.
Polanyi adds a quieter layer still: researchers know more than they can state. A skilled architect reads a drawing the way a fieldworker senses when an interview has drifted into performance, or a lab technician recognises contamination before any formal protocol flags it, or a curator detects a relational tension no checklist could have anticipated. Such competence is neither mystical nor methodologically trivial. It is embodied, acquired through practice, and it sits at the centre of the tension that environmental psychology, design research and artistic research all inhabit between formal method and situated expertise; the challenge is not to eliminate tacit judgement but to make its role inspectable wherever this is genuinely possible. Feyerabend pushes the critique of methodological uniformity further still. His argument against a single scientific method is routinely caricatured as relativism, yet its stronger implication is historical: scientific breakthroughs have frequently emerged by violating norms that later histories present, retrospectively, as continuous method. The lesson for transdisciplinary work is not that anything goes but that methodological legitimacy should answer to the problem at hand, to the evidence available and to the form of accountability required, rather than to ritual conformity.
This genealogy loops back to the first essay: categories shape evidence long before any measurement is taken. a variable is never simply found but constructed through prior decisions about what can be counted, observed and compared. When an indicator stops working as a proxy and begins substituting for the reality it was meant to help interpret, something has gone quietly wrong that no amount of additional data will fix on its own. The politics of missing data belongs here too, where absence can arise from non-existence, non-observation, exclusion, technical failure or plain institutional indifference, and each carries a markedly different epistemic and political weight. The contemporary extension of this genealogy lies in the infrastructures through which validation now travels — databases, dashboards, rankings, automated models, repositories, citation systems — so the quality of a claim depends not only on the original moment of observation but on its provenance, its metadata, its transformation, its retrievability. A dataset can be methodologically sound yet epistemically weakened once its processing history disappears; a model can be statistically robust yet institutionally opaque if its assumptions cannot be inspected. This longer arc deserves its own name, UncertaintyPassage: doubt itself changes shape as information moves from field observation to model, to report, to decision. A mature field is defined less by the absence of uncertainty than by knowing where it is uncertain, why, and what evidence would be sufficient to change its position.
Feyerabend, P. (1975) Against Method. London: New Left Books.
Kuhn, T.S. (1962) The Structure of Scientific Revolutions. Chicago: University of Chicago Press.
Peirce, C.S. (1931–1958) Collected Papers. Cambridge, MA: Harvard University Press.
Polanyi, M. (1966) The Tacit Dimension. Chicago: University of Chicago Press.
Popper, K. (1959) The Logic of Scientific Discovery. London: Hutchinson.
