Repeat actions by expert users are slowed by motion

What it is

The first time a detail opens, 300 ms of transition is teaching space; the tenth time, the same clip only lengthens a road already learned. Experts are slowed on repeat actions not because the motion is “too long for anyone,” but because learning is finished and motion is still charging at lesson speed. The abuse is treating a one-shot spatial lesson as a toll on every passage.

Why it happens

Novices use the transition to build a map and an identity; experts already have the map, and the next act is planned before the clip starts. The motion clock sits between plan and hit. Experts hurt more than novices because their plan density is higher and the opportunity cost of waiting is larger. The same milliseconds explain for a novice and rub for an expert.

Preference studies that only collect first impressions will score the motion as a plus and never see the tenth-time tax. In logs, inter-click gaps on expert paths pin to the animation’s floor instead of keeping falling with fluency.

Studying it

Split novice versus expert, or take the same person’s 1st, 5th and 20th trial. Dependent measures: task time, taps attempted during the animation, reports of being held. Independent variables: fixed duration versus shrinking with repetition / skippable. The point is not to let first-exposure preference lock everyday duration.

Where it stops holding

• On genuinely exploratory paths the expert still needs the spatial lesson, and slowdown is slight.
• High-consequence, rare confirmations can keep lesson speed.
• If experts can skip on first touch, the slowdown lands mainly on people who do not know skip exists or whose skip is unreliable.

Applying it

• On obviously repeated paths (list ↔ detail, tab switching, repeated save) let motion shrink within the session, or switch to a fade after the first time.
• Do not lock the duration experts pay every day to the mean liking from a new-user test.
• Check: time twenty trials with someone who walks the path daily. If the gap stops falling and pins to animation duration, that is a repeat tax.

Related

• Same group: F7.10.1 Stacked motion lengthens total wait · F7.10.3 Motion should yield to a faster next action
• Nearby: A11.04 Novice versus expert behaviour · F7.02.2 Motion that runs too long blocks the next action · F7.11.4 Forced motion feels slow in high-frequency use
• Search terms: expert slowdown · repeated path · motion tax