Typically, many or most people these days search for phrases or ask questions. It's highly successful in Google to simply ask a question and it's my main method of searching. Many of these phrases or questions will contain some words using less than the 4 allowed. So instead of returning a failed search with an annoying and potentially confusing error - why not just ignore any words below the minimum characters and at least return results with the other words a user searched for?
For example: The following, perfectly legitimate real-world searches on this IPS Community just fail with an error message in a red box.
- how can i upgrade my ips board?
- how much does it cost to buy ip.board?
- what is ip.content?
These are searches from people interested in buying. Similar searches on my ip.board and every one else's result in the same disappointing results. We all know people soon get frustrated and go elsewhere don't we?
So instead of frustrating our users, can't the search simply ignore all words below the threshold and return at least some results?
The results page could still have an advisory box saying that certain words were not used in the search.
So now searches for the three examples I mentioned will all produce some results and the advisory box can subtly inform and educate users that they need to use words longer than 4 (or whatever it's been customised to) letters.