SERVQUAL Gap Model (Parasuraman, Zeithaml & Berry)

Perceived Service Quality = Perception of service delivered − Expectation of service

The customer-facing "Gap 5," sitting atop four internal gaps (management's misread of expectations; the design gap; the delivery gap; the communication gap that over-promises). Quality is the difference the customer perceives, not an absolute.

Difference form, same as expectancy-disconfirmation, but the model's real contribution is the chain of upstream gaps that produce it — and one of them is Gap 4: external communication vs actual delivery (marketing that raises expectation the operation can't meet is a self-inflicted quality gap).

Transfer. For an awareness operation this names a discipline directly: your own promotion is Gap 4. Every over-claim in a post widens the expectation term and lowers perceived quality of whatever the reader then gets — the marketing manufactures the disappointment. The honest-scope move (pre-revenue, no fake numbers) is Gap-4 hygiene, not modesty.

Kin: illustrative-formulas · expectancy-disconfirmation · delivery-craft P14 · being-seen-reliably.

Source: A. Parasuraman, Valarie Zeithaml & Leonard Berry — "A Conceptual Model of Service Quality" (Journal of Marketing, 1985) and the SERVQUAL instrument (Journal of Retailing, 1988)