Are ''updating results ,please wait' modals really needed to indicate a change on a search-results page?

Question

Consider a search page (say kayak.com for a good example) , with lots of options/filters. Filtering updates the results through Ajax, so without a page refresh.

On most of those sites, after (de)selecting an option/filter a 'please wait while updating results' modal appears. Presumably to:

• let the user know the action was successfully received
• to give the user something to do while waiting
• to disable all other actions possible clicks for a moment, ensuring a successive order of actions event taken (in contrast to mlutiple ajax-calls potentially overlapping if the user selects another filter before the previous click has returned a result.

To me this all comes down to the fact that the page needs some noticable time to update, say a second.

I'm wondering if it would still be considered best practice to show such a notice if waiting time was reduced considerably. (Thinking ~100ms including clientside updates)

On the one hand I feel such a modal slows down the flow of the user. On the other, it may give a good indication (reflection point) for the user that the next results-page shown is the result of his/her action.

What do you think?

Answer 1

Informing users what's going on is never wrong. Assuming that we’re within time limit (<100 ms) and do not need to do anything is always wrong.

How can you tell how long it takes for user X to download content Y from your site Z at any given moment? There must be at least 200 unknown variables here that you do not have control over. That’s the reason we always inform our user what is (and could be) going on. If everything is ok, the message will never show and we’re home free. And that’s true 990 times of a 1000. But when it fails, we want our users to trust what we’re doing and we display that message telling them we can be trusted. Our users know they’re in good hands and we get all the money.

Answer 2

In theory constant communication to the user is never wrong, as mentioned above. However, it comes down to what you display. If you are displaying a sentence that might say (long winded example):

"Please wait, your search results are being updated. This shouldn't take long"

If the search lasts long enough for the message to be read, that's great. But shorter search times frustrate users as they don't have time to read the whole message, which is where the use of an icon might come in handy.