A final state does not describe a trajectory.

Two experiences can end at the same point

Two products can receive the same final intensity, comfort or liking rating and still produce perceptually different experiences.

A sample that begins cold and warms during use is not necessarily equivalent to one that begins at the final temperature. A product can deliver a sharp peak, a slow onset or a long aftereffect. Packaging, texture, sound and irritation can change as the product is handled or consumed.

The final rating compresses the path into one number.

Time can be part of the mechanism

Sequence changes perception. Adaptation changes intensity. Contrast and carryover change what follows. Temperature changes product physics and, in some cases, the perceiver. Repeated-use studies introduce learning, familiarity, maintenance, satiation and novelty loss.

In orosensory research, temperature can alter both the stimulus and perceived intensity, with effects that differ across people (Bajec et al., 2012). More broadly, time-intensity and temporal-dominance methods were developed because a single endpoint can hide meaningful dynamics (Cliff & Heymann, 1993; Pineau et al., 2009).

Measure the path when the path could change the decision

Temporal methods are not automatically superior. Continuous ratings can change attention and task demands. Repeated questioning can alter the experience. Some products and decisions do not require a detailed time course.

The useful question is whether onset, peak, duration, sequence, adaptation, recovery or repeated exposure could change the inference. If the decision concerns first contact, a first-contact measure may be enough. If it concerns the full use episode, aftereffects, repeated use or adoption, the evidence needs a time axis.

Possible approaches include time-intensity, temporal dominance of sensations, temporal check-all-that-apply, repeated discrete ratings, event-based logs and repeated-use designs. The method should match the mechanism and the burden the task places on participants.

A final state is a useful observation. It is not always a complete description of what happened.