Two seconds. It doesn’t sound a long time, does it? Who worries about a couple of seconds?
Maybe you should.
We have security doors at my workplace which require you to swipe your pass to enter, and require you to hit a release pad to exit. Activating the door release disables an electromagnet for a short while so the doors can open.
Recently, the doors on our floor needed maintenance, and the electromagnet was changed. For some reason, the new magnet held its charge for a couple of seconds after the release.
This was incredibly frustrating and annoying. I had got used to being able to hit the release and go through the door immediately. I continually found myself held up. It jarred. Every time. Even when they improved it so it was only a serving instead of two, it was still enough to be noticeable and annoying.
What’s my point here? Now think about your user interface. Does it appear to respond instantly, or do you have that clingy electromagnet? As a developer, it’s easy to think “that’s only a couple if seconds – surely that’s good enough/doesn’t matter.” If you don’t care about your user’s perceptions, you may be right.
If you want your users to be able to focus on their task, that two seconds is a distraction. It makes them think about your interface rather than what they’re trying to achieve – and those thoughts are not likely to be complimentary. It’s even worse – because you’ve distracted them, you’ve broken their train of thought so you’ve probably slowed them down by more than just the couple of seconds.
When it comes to responsiveness of interface, the human brain is amazingly sensitive. Don’t fall into the trap of “it’s only a couple of seconds.” Shave it down to a fraction of a second so you appear to respond instantly.
Your users won’t notice. And that’s one of the best compliments possible.