Deletion Confirmations - Making clear what you will lose?

Question

I am currently working on an error prevention concept for a Windows Forms application.

When the user is going to delete an object, how important is it to tell what the exact consequences are? In my application, other data can be tied to this object, data that might or might not be present. E.g. a "person" object can have related "finance" data stored. Losing this data without knowledge can result in a lot of work lost.

How should I communicate this in a confirmation dialog?

1. Just being generic and rely on the user knowing what he is doing?

Are you sure you want to delete this person? [Yes][No]

2. Always assuming that there is related data? (without checking if there actually is)

By deleting this person you will also lose related financing and payout data. Are you sure you want to delete this person? [Yes][No]

3. Exactly stating what will be deleted

By deleting this person you will also lose the following related data: financing, payout. Are you sure you want to delete this person? [Yes][No]

Answer 1

My suggestion:

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Delete John Doe?

You will lose his financing and payout information.

[Cancel] [Delete]

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1. Make clear what action will occur.
2. Use verbs in the text.

Answer 2

By deleting this person you will also delete (lose) the following related data:
financing - x records
payout - y records
Are you sure you want to delete this person?
[Cancel] [Delete]

And I would make Cancel the default (enter key)

Answer 3

The answer, not surprisingly, is "it depends on the app". (eg how catastrophic is the loss, is it recoverable, how familiar are users with the app, and other parameters that are specific to your application).

But the good news is, you've already laid out the options very thoughtfully in order of progressive levels of disclosure, so you're 90% of the way there.

The only remaining step is to place yourself in the user's position and ask, what would I want to know to complete this task?.

How you answer that question depends on how much time, experience and budget you have. You can use your own intuition. You can interview users, or conduct tests. But when you feel confident that you can answer that question, I would bet the farm that the answer to what level of disclosure will become forehead-slappingly obvious to you.

Answer 4

Loss of data is classified with the highest of severity when it comes to design issues. So only go with option 1 if you are 100% sure that the user will know what he is doing.

Option 2 will lead to frustration. The last thing you want to tell your users is that an action may have negative consequences. They'll immediately hesitate, and wish that you'd spell out said consequences. This will lead to a lack of user confidence.

Option 3 sounds good, but can you present it in a more natural way? When you visualize "the person", can you include snippets of the financial and payout information? That'll let the user know that the data is associated without making it sound mechanical.

Also, whenever dealing with data loss scenarios, the ability to undo is a must. People mis-click, or change their minds pretty often.

Good luck!

Answer 5

I agree with Blam and would like to add to his response (I don't have enough cred to "Add a comment" yet).

If space is not a concern, and deleting is not a regular occurrence, you might consider a recycle bin to allow the user to restore the data. You need to be concerned with duplicates on a restore - you wouldn't want to restore a duplicate and wipe out a newer entry. There are a number of ways to handle this, and it's arguably more work than you've bit off here. That one time the user really needs to get that data back makes it worth the effort.