How to prevent accidental button press?

Question

We have an app that logs tasks of workers and they're able to indicate the start / stop of the task by clicking "Start" or "Stop" (like a in a stop timer).

This "start / stop" time must be accurate (they cannot amend) as the system will record their actual timelog. However, they may accidentally press "Start / Stop" which will log an incorrect timing and they're not able to amend it.

Is there a way to prevent accidental press of this critical button?

Some ways I can think of is:

1. Always have a confirmation dialog at every press. E.g. "Are you sure you want to Start / Stop Task at XX:XX time. [Cancel] [Confirm].

2. Don't use a button but some other methods like a slider to Start / Stop?

3. Make it the press sensitivity low.

Am not sure what will work best or if there are other methods?

Answer 1

Do not prevent accidental press. Incorporate multiple starts/stops to the overall duration calculation and separate timer and task controls.

For example:

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This approach will turn “mistakes” to more data and will assign less duties/worries to workers.

Answer 2

I disagree with the warning message because the button is going to be used very frequently and the extra confirmation will annoy users. Furthermore the confirmation will become a habit after some time and it will loose much of its use.

I also disagree with the low sensitivity because this will require an action that is difficult to perform and some users will be frustrated.

I agree with the slider solution since it is relatively easy to use and will reduce significantly the accidental pressing.

However you can not prevent 100% the error so you have to provide an undo function, so that users can correct their errors. After the start is activated, provide just bellow a cancel option with small fonts and ask for confirmation when the cancel is pressed.

Answer 3

Do not use confirmation dialog.

You have few more options:

• Ugly "On/Off" swiper, like in configuration entries
• Nicer swipe button, like in unlock or accept incoming call
• long press button (start)
• Long press button with confirmation or more options (stop/pause)

^{download bmml source – Wireframes created with Balsamiq Mockups}

Answer 4

I think you have covered the conventional methods, but one that you can consider with mobile devices is a more complex gesture (such as those for the lock/unlock screens) that can prevent accidentally button pushes and are precise enough to be easily learnt by the user.