Week 10 Session: The Button With a Guard Rail
Adding exactly one proportionate obstacle to one of the five buttons from Week 4's reversible-to-irreversible table.
26 April 2027
Week 4 placed five buttons on an axis from reversible to irreversible and asked you to name what each one was actually claiming. This week takes one of those five and asks what, if anything, stands between the press and the consequence it claims.
Most consequential buttons have nothing standing between the two. A delete button and a confirm-purchase button can sit at the same weight on the axis and still differ completely in what it costs to press them by accident.
Five ways to add friction#
- Confirmation — a second, separate press, asking whether you’re sure.
- Hold-to-confirm — the press must be sustained for a fixed duration rather than instantaneous.
- Delay — the action is queued and only takes effect after a fixed interval, during which it can be reversed.
- Re-entry — the user must re-type or re-select something they already specified, rather than simply pressing again.
- Typed confirmation — the user must type a specific word, or the name of what they’re removing, before the button becomes active.
Each of these costs the presser something — time, attention, an extra step. None of them is free, which is exactly why the obstacle has to be chosen for the specific button, not applied by default to every button on the axis.
One button, one obstacle#
Take one button from your Week 4 table — pick one that sits toward the irreversible end. Add exactly one obstacle from the list above, or one of your own, before its consequence fires. Don’t add two. Don’t soften the button itself; the obstacle sits between the press and the result, not on the button.
Justify the obstacle#
Write, specifically for this button:
- what the obstacle actually costs the presser, in time or attention
- what it would take for the obstacle to fail to stop an accidental press — a case where someone gets through it without meaning to
- why a weaker obstacle would have been insufficient for this button’s actual consequence
- why a stronger obstacle would have been unnecessary friction on a button people also need to press on purpose, often
Submit the button, the single obstacle you added, and the four answers. An obstacle you can’t justify against both failure directions is a guess, not a guard rail.
The spec
What you bring to the session. Written so a reader can tell whether it has been met without asking you.
- you have picked one button from your Week 4 five-button table and restated its place on the reversible-to-irreversible axis
- you have added exactly one obstacle before its consequence — for example confirmation, hold-to-confirm, delay, re-entry, or typed confirmation
- you can justify, in specific terms, why that exact obstacle is proportionate — not too weak for the consequence, not more obstructive than the consequence warrants
Teaching team
- Idris Fenn — tutor