When the instructions are "check all that apply," should there be a "none" checkbox?

Question

I frequently see surveys with multiple-select questions that tell the user "check all that apply," and have a final checkbox for "none of the above." Is there any evidence or expert opinion as to whether this is a good idea?

I assume its purpose is distinguish people who skipped / ignored the question from ones who decided that none of the answers apply. But it contradicts the literal instructions, and users may not even see the "none" option if they don't think there's any reason to read through the whole list. For example, if the instructions say "check the flavors of ice cream you like" and I hate ice cream, I probably won't read the whole list of flavors and see the "none of the above" box at the end.

It seems like this has the potential to confuse people, and generate a lot of false negatives (people who did read the question, but didn't check "none").

Answer 1

I think "None of the above" should not be a checkbox since by virtue of being a checkbox placed along with other options, it inherently means it can also be "checked" in addition to the other checkboxes, which can be lead to an invalid state. For example, what if the user checked "Vanilla", "Strawberry", "Butterscotch" and also "None of the above"?

My recommendation would be to make the "None of the above" a link or a button that says "Clear all" or something like that.

So if the user wants to clear all the items he has selected, he just has to click on this button/link that un-checks the selection.

Check out the image below. Each option just shows different text representation for the same action - undo selection.

Answer 2

I think there some potential use cases where this question might apply.

1. Users must select an answer: In this case the answer is self explanatory since the user would have to select something to continue on to the next question or to submit the form. Hence, the "none of the above" option gives him a quick escape route if he doesn't agree.
2. The user has to provide a opinion: This case arises when the survey wants to ensure that the user is always provided with the option to provide an opinion if he doesnt agree with any of the options. The last checkbox "none of these apply" gives him an option to do that

With regards to your comment about not answering a question of "which icecream do you like", I do agree if the question is not relevant to you you would just ignore it but if the survey person wanted your opinion none the less an easy escape option like the last one is the best bet.