Where does focus collide?

The point to which a lens or curved mirror brings parallel light rays together, or from which they appear to diverge. Kepler introduced the word focus, Latin for hearth or fireplace, in his 1604 Ad Vitellionem paralipomena, quibus astronomiae pars optica traditur, naming the burning point where converging rays gather their heat and, by extension, the defining point of a conic section. The referent is a location in space fixed by the geometry of a curved surface, marked by its distance from the lens (the focal length), and it has nothing to do with the highlighted part of a sentence, a firm's narrow market, or a person's motivational bent.[1]

Unit

A single convergence point, located by its distance from the lens or mirror (the focal length)

Recovery means

Not applicable

Measured by

Located by tracing rays or by finding where a collimated beam forms its smallest spot, and quantified as focal length

The part of an utterance a speaker marks as carrying the most newsworthy or contrastive information. Halliday named information focus in the 1967 second part of Notes on transitivity and theme in English, treating it as the point the speaker presents as the peak of new content within an information unit, signalled in speech by prosodic prominence. Rooth's 1992 A theory of focus interpretation gave it a formal treatment in which a focused item evokes a set of alternatives it is being contrasted against. The referent is a property of how meaning is packaged in language, and it is not a point in an optical system, a firm's competitive scope, or a self-regulatory orientation.[2][3]

Unit

The marked constituent of an utterance, one focus domain per information unit

Recovery means

Not applicable

Measured by

Identified from prosodic prominence such as pitch accent, and from question-and-answer or contrast tests that reveal which part is highlighted

A competitive approach in which a firm chooses a narrow slice of the market and serves it better than rivals who aim broadly. Porter named focus as one of three generic strategies, alongside cost leadership and differentiation, in his 1980 Competitive Strategy, defining it as the deliberate choice of a narrow buyer group, product line, or geographic market as the arena of competition. The referent is a decision about the breadth of a firm's competitive scope, judged by market share and margin within its chosen segment, and it does not name a point of converging light, a highlighted piece of speech, or a person's motivational orientation.[4]

Unit

A firm's chosen competitive scope, one narrow target segment

Recovery means

Not applicable

Measured by

Assessed by the breadth of the served market and by segment-specific share, margin, and fit relative to broad-line competitors

A person's orientation toward the goals they pursue and the way they pursue them. Higgins introduced regulatory focus theory in his 1997 Beyond pleasure and pain, distinguishing a promotion focus, oriented to gains, growth, ideals, and eager approach, from a prevention focus, oriented to safety, duties, losses avoided, and vigilant caution. The referent is a motivational disposition that shapes how someone frames and works toward outcomes, measured by self-report and by task framings, and it is unrelated to a point of converging light, a marked part of an utterance, or a firm's competitive scope.[5]

Unit

A person's motivational orientation, scored along promotion and prevention dimensions

Recovery means

Not applicable

Measured by

Assessed by self-report scales such as the Regulatory Focus Questionnaire and by task framings that engage gain versus loss concerns