Five Control Parameters: Operationalising the set R · E · I · G · B — carriers, units, measurement procedures and limits of applicability

Parametric descriptions of complex systems are unwarrantedly long-lived: while a quantity is not measured, every experimental outcome remains compatible with it and the description cannot be refuted. This paper proposes an admission rule and applies it, first of all, to its own parameter set. A parameter enters a model only if four conditions hold simultaneously: a physical carrier is named, a unit is stated, a measurement procedure is described, and a range of applicability is given together with what ceases to hold beyond it. To these four the paper adds a fifth requirement drawn from metrological practice — that the dominant contributions to the uncertainty of the stated procedure be identified, so that the parameter arrives with a stated doubt rather than as a bare number. Under this rule five control parameters are operationalised: R, rhythm (including its frequency component); E, energy; I, information; G, geometry; B, barrier. For each, the carrier, the unit, the instrumental or counting procedure, the limiting factor and the principal sources of uncertainty are given. Two cases are treated separately in which a symmetric and a directed quantity meet under one name — mutual information versus transfer entropy, and frequency versus regularity — and a rule is stated: two sides of one quantity are distinguished inside the parameter, neither merged nor split across separate parameters. The admission rule is then shown working against the author's own interest: the symbolic expression that was the most striking line of the earlier edition of this work is withdrawn as dimensionally inconsistent and prohibiting nothing. Finally, a quantitative result is given that makes the barrier parameter practically useful: at room temperature a change of 0.2 eV in the energy barrier changes the lifetime of a state by roughly a factor of 2·103, and the whole range from fractions of a second to millennia is contained within 0.6 eV. This is the author's manuscript version, submitted to a peer-reviewed journal and deposited here to establish the date of the work. Article type: methodological paper. No new measurements are reported; no research subjects are involved.