In an interactive prototype there often tends to be elements displayed that don't function the way they eventually will, due to time constraints, not being a part of that particular user test, etc. But the elements (buttons, links, anything that could potentially be interacted with) still appear for the user. And because they are there, some user will at some point click on one, even when directed toward tasks that don't correspond with that element at all.
What is the best way to handle when users try to interact with nonfunctional elements?
I've thought of a couple possibilities, but am unsure whether or not any of them are viable or if there is a better solution I am wholly unaware of.
For example, the element (say, a button) could be visible, but not react at all when a user clicks on it. The user would quickly become aware that is doesn't do anything at the time.
The button could show a tooltip or some visual indicator that that specific function isn't available at this point in time.
We could also maybe ensure that every interactive element that does work includes a hover state, where the ones that don't function don't have a hover state, indicating before a click that they won't respond.
But to reiterate, what is the best way to handle inadvertant user interaction with nonfunctional elements in an interactive prototype?