MKTG6007 · Consumer Behaviour
Perception
Before a consumer can like, learn or buy anything, a stimulus must run a four-link chain: it has to be encountered (Exposure), noticed (Attention), sensed (Perception) and understood (Comprehension) — the EAPC chain. Each link is a precondition for the next, so marketing that fails does so because one link broke. This chapter works through all four: how exposure is managed (and how consumers dodge it with zipping and zapping), why attention is limited, selective and divisible and fades with habituation, the two thresholds that govern what registers — the absolute threshold and the Just Noticeable Difference (JND) with Weber's Law — and how the mind organises stimuli, sells through all five senses, then assigns meaning. The whole chain is a diagnostic ladder: for any campaign, ask at which link it fails.
What this chapter covers
- 012.1 Exposure — physical contact, selective exposure (zipping & zapping)
- 022.2 Attention — limited, selective, divided
- 032.3 Habituation — attention fades with repetition (ad wear-out)
- 04Perception & the thresholds — absolute threshold, the JND
- 05Weber's Law — the JND is a constant ratio of the original stimulus
- 062.4-2.6 Perceptual organisation, sensory marketing & comprehension
Worked example: read a price change through Weber's Law
- +1State Weber's Law. The JND — the smallest change a consumer can notice — is a roughly constant ratio of the original stimulus, not a fixed amount: a larger base needs a larger change to be noticed.
- +1Hide the negative change. To shrink the $40 hamper unnoticed, keep the reduction below the JND — a small % on a high base barely registers (shrinkflation done quietly). The same dollar trim on the $2 item is glaring, so do not shrink that one.
- +1Highlight the positive change. To signal the premium recipe, push the cue at or above the JND — a clearly different pack, a visibly upgraded design — so consumers actually perceive it.
- +1Refresh without losing recognition. Change the logo enough to feel new, little enough to stay “you” — the JND is the line between a fresh update and an unrecognisable one.
Key terms
- EAPC chain
- Perception's four links — Exposure → Attention → Perception → Comprehension (contact, notice, sense, interpret). Each is a precondition for the next, so a failed message broke one specific link: never seen, ignored, too faint, or misread.
- Habituation
- The gradual decrease in responsiveness to a stimulus after repeated exposure — a learned tuning-out, not a loss of sensory ability. It is the engine of ad wear-out: the tenth viewing of a spot does far less than the first. Marketers fight it by refreshing the creative, channel or format.
- Absolute threshold
- The minimum intensity of a stimulus needed to detect something versus nothing. Below it the stimulus may as well not exist — a sign too small or a sound too quiet never even enters the EAPC chain.
- Just Noticeable Difference (JND)
- Also the differential threshold — the smallest change between two stimuli a consumer can perceive. Marketers keep negative changes below the JND (shrinkflation) and push positive ones at or above it; a logo refresh lives right on the line.
- Weber's Law
- The JND is a roughly constant ratio of the original stimulus, not a fixed amount: the bigger the starting stimulus, the bigger the change needed to notice it. $5 added to a $10 item is glaring; $5 added to a $100 item barely registers.
Perception FAQ
Why is EAPC a chain and not a list?
Because each link is a precondition for the next, so the chain can break at exactly one point. A billboard nobody drives past gets no exposure; an ad you skip gets no attention; a jingle too quiet gets no perception; a clever pun in a language you don't read gets no comprehension. Diagnosing which link broke, then prescribing the fix for that link, is the analytical move the assessments reward.
What is the difference between the absolute threshold and the JND?
The absolute threshold is about detecting something versus nothing — the faintest stimulus you can sense at all. The JND (differential threshold) is about detecting a change between two stimuli. Weber's Law turns the JND into something almost calculable: the change needed to notice is a constant ratio of the starting level, which is why the same dollar change feels huge on a cheap item and invisible on an expensive one.
How do marketers actually use the JND?
In both directions. They keep a negative change below the JND so it goes unnoticed (shrinkflation — quietly shrinking a candy bar), and push a positive change at or above the JND so it is seen (a clearly bigger size-up, a visibly greener logo). For a refresh they walk the line: change enough to feel new, little enough to keep the brand recognisable.
Why does the same ad stop working after a while?
Habituation. Repeated exposure produces a learned decrease in responsiveness — you can still see the ad, you just stop noticing it. That is ad wear-out, and a “50% OFF” sign that is always there stops reading as a deal. The cure is to refresh the stimulus (vary creative, channel, format, add novelty) so the brain re-engages while the brand stays recognisable.
Exam move
Use the EAPC chain as a diagnostic ladder on any campaign in your LookBook or report: name the link that fails (exposure, attention, perception or comprehension) and prescribe the fix for that link — that is the theory-to-evidence move markers reward. Keep the JND and Weber's Law as a sharp analytical tool: photograph a pack that has shrunk or a logo that has changed and argue whether the firm kept it below or pushed it above the JND, and why. Tie attention and habituation to your own life — a banner or notification you have stopped noticing is habituation in action — and remember that miscomprehension rises when any MAO factor is low, so the fix is to lift motivation, support ability and protect opportunity.
