Response Time Research:

Robert B. Miller. Response Time in Man-Computer Conversational Transactions. In Proc. Sprint Joint Computer Conference, Montvale, NJ, 1968. AFIPS Press.

Miller's classic 1968 paper, presented at the Fall 1968 Joint AFIPS Computer Conference, on minimal response times, has been cited by Jacob Neilson, James Martin, and many others. Researchers from Miller on have been studying the psychological effects of response time on the user (Bergman, et. al., Grossberg, et. al., Henning, Miller, Shneiderman, 1992)

I have been familiar with Time Periods for a long time, probably running across them in James Martin's Design of Man-Computer Dialogues . I have not been able to find a copy of Millers paper online. If you know of one, please let me know so I can provide a link.

The Time Periods:

Time Delay in Seconds User Sense of Interaction Specific Feedback Needed to Keep Attention User Response to Delay
One Tenth ( 1/10) Instantaneous None User Deeply Focused on
Contents and Inputs
One Second (1.0) Site is very Responsive. User arrives on new page without delay None Scans to see page contents and features
Five Seconds (5.0) Site is Slow. Maximum for keeping User attention. Warnings about lengthy downloads of pictures and information User annoyed but stays focused if content is of high interest. Does other tasks while waiting for response
Greater than Ten Seconds (10.0) Site is too slow for any use Site Redesign Moves to another Site


Greater then 2 minutes: Go get a cup of coffee, go to the bathroom, do some other work, etc,.

Greater then 10 minutes: Put it off, start it and let it process overnite.