effectivity

Compiled with AI assistance and selectively reviewed. Please consult the cited passages; the books remain the authoritative source. About this companion

Editorial synthesis · provisional

Definition

An effectivity is the organism-side capacity that complements an environmental affordance and makes the corresponding action realizable. In Turvey’s ecological formulation, capabilities include strength, coordination, skill and bodily or tool-extended reach. The relation depends on the particular animal and setting, rather than on object geometry alone or an abstract ability possessed independently of conditions.

Explanation

RB2 distinguishes action-scaled possibilities from geometric fit. A step below a body-length threshold can still be unclimbable when strength or balance is insufficient. Effectivities name the capacity side of this relation: the dexterity to operate a handle or the ability to reach and bite food.

Turvey’s dispositional account pairs an environment’s offering with an animal’s matching capability. Tool use and learned skill can change that capability, requiring perception to recalibrate as bodily possibilities change. These are relational achievements, not a list of permanently available actions read directly from the object alone.

The source qualifies the backpack-and-hill example because experimental demand has challenged its perceptual interpretation. That contested illustration should not become decisive evidence for the definition. PB’s formal affordance treatment supplies related body–world context without independently proving Turvey’s proposal or every claimed top-down perceptual effect.

Scope and attribution

A proposed Turvey-attributed ecological subentry, not a general claim about effectiveness.

AB — The Actual Book

Turvey’s pairing is named within the ecological-perception note.

Occurrence locators: Notes: 242.

RB2 — The Real Book, Volume II: Becoming Is Being

Effectivities complement affordances through situated capacities; contested demonstrations stay qualified.

Occurrence locators: 70, 71, 73.

Background used in the editorial explanation

Named theories and mechanisms are distinguished from neighboring background, homonyms and the author’s own synthesis. Reproduced AI passages retain their separate voice.