CHAPTER 4 Culture of Performance
Because if you can’t see the full length of the line, and you seem to be
moving, you’re less likely to become frustrated. In fact, it turns out people
are happier in a longer line that moves quickly than a shorter line that
moves slowly even when the total time waited is the same.
More than the numbers, what truly matters is how a user perceives
your site. Does it feel like the site loads quickly? Do the interactions feel
immediate and snappy, or delayed and sluggish? We can apply the same
sort of thinking to the sites and applications we build. In fact, some very
successful apps have done that.
At the end of 2011, Mike Krieger, co-founder of Instagram, gave a pre-
sentation called Secrets to Lightning-Fast Mobile Design^30. During his talk, he
focused on three secrets:- Perform actions optimistically
- Adaptively preload content
- Move bits when no one’s watching
It’s worth exploring each in a little more detail.Perform actions optimistically
Let’s say a visitor to your site is going to leave a comment. To do so, they
click a button that submits the form. When they do, two things happen.
The form, using AJAX, sends a request to the server and a loading graphic
appears to tell the user their submission is in process. When the script
hears back from the server that the task completed successfully, it updates
the page alerting the visitor.
This is the way it’s typically done, but maybe it’s not the best way. That
request, particularly on a high-latency network, can take several hundred
milliseconds — a very noticeable delay for the person trying to submit their
comment.30 http://smashed.by/fast-mobile