Slow response-time cheat sheet

Question

Does anyone have links to current and historical papers and authoritative links (statistics and blog posts) regarding response-time for user interfaces?

Naturally the authoritative link is Human factors design criteria in man-computer interaction

Some key quotes include:

[Regarding] response to request for next page. […] Delays of longer than 1 second will seem intrusive on the continuity of thought.

And

Assume an inquiry of any kind has been made. The user – and his attention – is captive to the terminal until he receives a response. If he is a busy man, captivity of more than 15 seconds, even for information essential to him, may be more than an annoyance and disruption. It can readily become a demoralizer – that is a, reducer of work pace and of motivation to work.

These quotes are 40 years old, yet so relevant today.

There is also Jacob Nielsen's authoritative excerpt.

I would like to collect all the links to this kind of research under this community wiki.

Next time you are told to ignore response times by your manager or build a feature that will slow down your application you can simply send them a link to this page.

Shurlock

Answer 1

I think the simplest answer was in an article by Jakob Nielsen where he defined the 10/1/.1 second rule in Response Times: The Three Important Limits. That article is based on a section from his book Usability Engineering. He's presenting further research and applicability to the web in several 2009 sessions, all linked to from 1.

Tilden

Answer 2

I came across these recently pertaining to website speed:

Men Need Speed http://www.websiteoptimization.com/speed/tweak/usability-criteria/

Study: Web Users Prefer Speed Over Customization http://www.websiteoptimization.com/speed/tweak/design-factors/

Bimbo

Answer 3

Similar to the link lavinio posted, Jakob Nielsen's recent article outlines a 0.5/0.1/0.5 second rule for hover times of dropdown menus.

http://www.useit.com/alertbox/mega-dropdown-menus.html

Tweeze

Answer 4

Saving Lives

I read this little article

To quote Steve Jobs:

"Well, let's say you can shave 10 seconds off of the boot time. Multiply that by five million users and thats 50 million seconds, every single day. Over a year, that's probably dozens of lifetimes. So if you make it boot ten seconds faster, you've saved a dozen lives. That's really worth it, don't you think?"

I think the same argument can be made for response-time on high volume sites.

Shurlock

After reading the quote from Stevie I kinda felt sad for him. – Uri

Answer 5

I just came across:

System Response Time and User Satisfaction: An Experimental Study of Browser-based Application (watch out its a PDF) by John A. Hoxmeier, Ph.D.

The summary of the findings are:

• H1 satisfaction decreases as response time increases [supported]
• H2 Dissatisfaction leads to discontinued use [supported]
• H3 ease of use decreases as satisfaction decreases [supported]
• H4 experienced users more tolerant of slower response times [not supported]

Shurlock

Answer 6

Jared Spool shares some results of research conducted at UIE about the importance of performing a goal rather than download time.

Since we conducted the original research five years ago, we’ve repeatedly discovered users are more interested in achieving their goals than having speedy page loads. Since goals are often complex and require the users to be thoughtful, the best designed sites seem to get away with slower-than-average pages.

The original research from 2001 he references is The Truth About Download Time by Christine Perfetti and Lori Landesman.

Syconium

That being said, response time is important. Just be sure that your user's needs are met foremost. – Syconium

If your pages are taking 15 seconds to load "It can readily become a demoralizer". People were a little more forgiving in the earlier days of the web when everything was slow. I think slow response-time is the first problem that needs to be tackled ... its certainly not the only one. – Shurlock