Is it not advisable to have a visible cancel option when performing a action such as delete

Question

I was reading about the guidelines for flyouts for Metro Design which state that:

Include just the action that the user initiated, such as Delete. Do not include the opposite action or a Cancel button; that can be achieved by dismissing the Flyout.

I do understand that there is an option to prevent the delete from taking place by clicking outside the flyout but assuming I was using the metro layout for the first time,i would get confused about what to prevent this from happening since i see no apparent cancel button.

So my question is: When performing actions like delete or say format which might be not be non reversible, wouldnt it be advisable to have a cancel button instead of relying on the belief that the user might know the alternate way to cancel the action (which happens to be hidden)

Answer 1

I do not like that guideline. Trying to be innovative with important user actions can be dangerous. I don't think there is any doubt that users are familliar with the "ok" and "cancel" options in such confirmation boxes.

A flyout with just one option (ie. "Ok") used to be containing information like ie. "You can't do that here." that doesn't activate an action.

People I know still have problems with closing a light box shown picture without a clear close action so what would happen with important decisions?

Answer 2

I also don't think that would be the best route to go down. For some users they may become under the belief that the only option is to delete the images and that they have no choice. Instead I would go for the traditional route of "Delete/Don't delete".

If you decide to use buttons also be careful about the wording as this could also be confusing to some users. For example, I found this article on the usage of the "Cancel" button: http://uxmovement.com/forms/killing-the-cancel-button-on-forms-for-good/

Answer 3

Jakob Nielsen's 10 Usability Heuristics for User Interface Design has two points I want to focus on that shows that not having a cancel - or emergency exit - button is a bad idea for usability.

User control and freedom
Users often choose system functions by mistake and will need a clearly marked "emergency exit" to leave the unwanted state without having to go through an extended dialogue. Support undo and redo.

Error prevention
Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.

from Jakob Nielsen's 10 Usability Heuristics

The alternative is to rely on an undo feature, but the fact that a user can delete (and will) information by mistake should be prevented in the first place.

The Usability Body of Knowledge lists these three principles of usable design under error prevention:

Error Prevention and Handling:

Forgiveness: Allow reasonable variations in input. Prevent the user from making serious errors whenever possible, and ask for user confirmation before allowing a potentially destructive action.

Error recovery: Provide clear, plain-language messages to describe the problem and suggest a solution to help users recover from any errors.

Undo and redo: Provide "emergency exits" to allow users to abandon an unwanted action. The ability to reverse actions relieves anxiety and encourages user exploration of unfamiliar options.

from Usability Body of Knowledge: Principals of Usable Design

So clearly there are substantial reasons to not remove the emergency exit paths as user will make mistakes.