The definition below each term is the collection's common coin; the links under it go to where the term earns its keep, and each site keeps its own inflection. Colour marks the destination site.
MatheMetaphor CommuniCoupling SocioRhetoric ExploRational
An utterance that does something — asserts, warns, promises, names. It is judged by whether it comes off; truth is one success condition among several.
where it lives Assertion · Lie · Gesture & response
also appears in Non-commutativity · Structure as medium & outcome · Idempotence · Punctuation of the sequence
An organization whose operations produce the elements its next operations use. What closes is the loop of production; contact with the environment continues.
where it lives Autopoiesis · Eigenforms · Laws of Form · Fixed points
also appears in Operational closure · Structural coupling · Structural holes · The strength of weak ties
Everyone knows p; everyone knows that everyone knows it; and so on without end. Coordination that needs the full tower is fragile, because no finite exchange of messages builds it.
where it lives Common knowledge · Two generals · Definition of the situation · Tribal signal
also appears in Common ground
A limit on what can vary. The productive ones generate: fourteen lines make the sonnet, and a conservation law is a physics of what cannot change.
where it lives Enabling constraints · Conservation laws · Generative constraint
also appears in Lagrange multipliers & shadow prices · Structural holes · Duality · Enumerating the combinations
Matching actions without instruction: each party converges because each expects the others to. Salience does the work that communication cannot.
where it lives Schelling points · Nash equilibrium · Double contingency · Kuramoto synchronization
also appears in Conway's law · The two generals · Boundary objects · Focal points
Recurring interaction that lets two systems' states constrain each other. Tight coupling transmits shocks; loose coupling absorbs them.
where it lives Structural coupling · Coupled oscillators · Near-decomposability
also appears in Synchronization · The three loops · Partial vs. general equilibrium · Decoherence
A proxy drifting free of the state it stood for. The measure still moves; what it measured no longer moves with it.
where it lives Goodhart's law · Surrogation · Palter
Output routed back as input. The loop gain picks the genre: below one, a thermostat; above one, an arms race.
where it lives Feedback loops · Homeostat · Vicious circles · Schismogenesis
also appears in The definition of the situation · Channel capacity · Delay & overshoot: the beer game · Niche construction
A requirement an act must meet to come off: the right speaker, the right circumstances, uptake at the far end. Truth sits alongside authority and sincerity, one condition in a set.
where it lives Assertion · Palter · Lie · Gesture & response
also appears in Frame-set
The definition of the situation that fixes which moves exist and what they mean. Change the frame and the same facts play differently.
where it lives Definition of the situation · Changing the representation · Making the familiar strange · Change of basis
also appears in Frame-set · Making the system an object · Listening for the back-talk · Setting the problem
The correspondence table between source and target: which part answers to which, and what falls through. The leftovers get named, because that is where the metaphor tears.
where it lives Isomorphism · Kernel · Systematic re-description
also appears in Distant analogy · The good regulator · Analytic continuation · The Chinese remainder theorem
Parts, couplings, and an update rule that together produce the phenomenon — something you can run. The collection's left column simulates mechanisms; its right column drills moves.
where it lives Schelling segregation · Preferential attachment · Beer game · Mechanism design
also appears in Categorical inequality · The black box · The homeostat · Heterarchy
A source domain lent to a target so its inference rules can be reused there. The loan is auditable — see mapping.
where it lives Homomorphism · Distant analogy · Comparing distant cases
also appears in Gödel incompleteness · Isomorphism · P vs. NP · The axiom of choice
An act performed in circumstances that void it: the words come out, the deed does not come off. Every page in the collection carries a misfire key — the conditions under which its own instrument reads wrong.
where it lives Assertion · Teachback · Signal detection
also appears in The four-cornered check · Frame-set · Counter-signal · Lie
An action drawn from a repertoire, practiced until it stays available under pressure. Where a mechanism is run, a move is made.
where it lives Premortem · Steelmanning · Counter-signal
also appears in Accepting the offer · Galois solvability · Generative constraint · Making the system an object
The system doing the distinguishing. Every description has an address, and observing the observer is a distinct operation with its own blind spots.
where it lives Second-order observation · Black box · Controllability & observability · Self-distancing
also appears in Eigenforms · Fourier decomposition · The primal distinction · Reflexivity
Expression keyed to situation and audience: one content, pitched for the courtroom or the kitchen. The collection's two skins are registers — catalog for choosing, laboratory for being inside.
where it lives One event, three codes · Copia · Counter-signal
also appears in Umwelt · Landauer's principle · Stochastic resonance · Logarithmic perception
An emission that carries information because it covaries with a state the receiver cannot see directly. It stays credible only while faking it costs more than it pays.
where it lives Costly signaling · Signaling games · Tribal signal
also appears in Stochastic resonance · Counter-signal · Compressed sensing · Quorum sensing
The value at which more of the same input yields a different kind of output. Below it, perturbations die out; above it, they propagate.
where it lives Epidemic threshold · Phase transitions · Granovetter thresholds · Complex contagion
also appears in Granovetter thresholds · Excitable media · Error catastrophe · Stochastic resonance
The number of states a system can distinguish or produce. Ashby's law: a regulator needs at least as much variety as the disturbances it must absorb.
where it lives Requisite variety · Good regulator · Entropy · Quantity before judgment
also appears in Latent space & embeddings · Copia · The algedonic loop · The curse of dimensionality
false friends
Six terms that sound shared across sites but carry different senses — the places this pidgin can lie to you.
In ExploRational, closure is a deliberation ending — well or badly; the Record grades it. In CommuniCoupling, operational closure is a system's self-reference: it produces the elements it runs on. A meeting can close without being closed in Luhmann's sense, and a system can be operationally closed while its questions stay wide open.
the two senses The Record's verdicts · Autopoiesis
The glossary's register (above) is tone keyed to situation. SocioRhetoric's fourth axis — regulation — is how tightly an act's meaning is pinned to the local occasion. Near-namesakes: one is about pitch, the other about play in the joints.
the two senses register, above · the regulation axis
In MatheMetaphor's signal detection, a signal is whatever must be separated from noise — a statistical object with a threshold. In SocioRhetoric, a tribal signal is an allegiance display whose accuracy is beside its point. Detecting the second with the first's machinery is exactly how it gets misread as a claim.
the two senses Signal detection · Tribal signal
SocioRhetoric's frame-set is a social act: it assigns parts and needs uptake. ExploRational's change of representation is a private one: re-encode the problem and different moves become available. The same word covers a move on people and a move on paper.
the two senses Frame-set · Changing the representation
CommuniCoupling's structural coupling is a history: two systems drift into fitting each other without exchanging instructions. MatheMetaphor's coupled oscillators exchange influence right now, term by term, in the equations. One is biography, the other dynamics — near enough to rhyme, far enough to mislead.
the two senses Structural coupling · Coupled oscillators
In CommuniCoupling, second-order observation watches how another observer draws distinctions. In the Reactor, an "observed" factor is one your purposes never touched but a factor you care about numerically depends on. Both are secondhand seeing; only one of them can be computed.
the two senses Second-order observation · The Reactor's observed factors