Should the Autocomplete let the user display terms that get 0 results OR should the Autocomplete only contain terms that would lead to results?

Question

A user uses Autocomplete to search for something. The number of results for the term searched (using the autocomplete) is zero.

Should the Autocomplete let the user display terms that get 0 results OR should the Autocomplete only contain terms that would lead to results?

Answer 1

Yes, to show the auto-complete item will allow the user to find out that there are no results quicker than they would if the item did not display. To illustrate I have provided 2 scenarios:

Scenario 1 (auto-complete items are shown regardless of the number of results):

1. User types first words of search terms
2. Auto-complete shows some suggestions
3. User selects auto-complete item before finishing search terms
4. The search results view is displayed with no results.

Scenario 2 (auto-complete items are not shown if 0 results):

1. List item
2. User types first words of search terms
3. Auto-complete shows some suggestions, but because there are no search results for the auto-copmlete item the user wants it is not shown.
4. The user keeps typing the rest of his query
5. User performs the search
6. The search results view is displayed with no results.

Now you could improve Scenario 1 by showing in the auto-complete item the number of results. This would allow the user to see that there were no results even faster.

Answer 2

You could show (at the top of the autosuggest) that no results match and then a separator, and then give some partial matches or the most popular choices. That way, they see no results were found but might see what they need anyway.

Answer 3

From a usability standpoint, autocomplete should really be using terms that exist, that will return results. Not sure why a user would want a field to autocomplete only to be told that there are zero results for that term. It's not very elegant.

Plus, as I fill in a field form and see terms suggested to shorten my typing and time, I am probably anticipating that those terms will give me what I want in the way of search results.