Frame 3: Minimise interaction cost
==================================

Spec: descriptive guidance, not a checkable rule.
It carries no forbidden and instead pair, and no `jig check` detector applies to it directly.
Section: Principles
Group: Frames

**Ask: what does this cost the user, counted?**

Interaction cost is the total physical and mental effort to complete a task: clicks, scrolls, pointer distance, keystrokes, waiting, reading, and anything the user must remember or go and find. Its virtue is that it is **countable**, which makes it the most checkable idea in this file.

Three reliable reductions:

1. **Keep related actions close, and targets large.** Per Fitts's law, time to hit a target falls as it gets nearer and bigger. Put the action beside the thing it acts on; keep targets at `--size-touch-target` or larger. Start-aligning the action also keeps it visible to screen-magnifier users.
2. **Cut distraction.** Banners, autoplay, unsolicited dialogs — cost charged against a task the user did not choose to pause.
3. **Cut choices.** Per Hick's law, decision time rises with the number and complexity of options. Fewer options, or a promoted recommended subset, produces faster decisions.

**Use it like this:** count before and after, and state it. "3 clicks + 1 scroll → 2 clicks" is reviewable. "Improved the UX" is not. See `P-10`.