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In a well-designed website, how long should users have to wait for pages to download?

Past studies:

Using the research that was available to them, Miller (1968), Bailey (1982) and Shneiderman (1984) recommended that the computer should respond to users within two seconds. Martin and Corl (1986) reported that with most data entry tasks there was no advantage of having response times that were faster than one second, and found a linear decrease in productivity with slower response times (from one to five seconds). With problem solving tasks, which are more like Web interaction tasks, they found no reliable effect on performance up to a 5-second delay.

With websites we have had all kinds of interesting maximum "wait time" numbers proposed over the last few years. Most were based on educated guesses, and most have proposed a number (e.g., 8 or 10 seconds) that took into account that loading Web pages would be much slower than the "two seconds" suggested in earlier studies. So how slow is too slow?

Many issues are involved:

One reason that acceptable response times are so difficult to determine is that people's expectations for acceptable response times differ from situation to situation. Users seem willing to wait varying amounts of time for different types of interactions. The amount of time a user is willing to wait appears to be a function of the perceived complexity of the request. For example, people will wait longer for requests they think are hard or time-consuming for the computer to perform.

Paula Selvidge and Barbara Chaparro at Wichita State University, and Gregory Bender at IBM, conducted a study to examine the effect of download delays on user performance. They used delays of 1 second, 30 seconds, and 60 seconds. They felt that longer delays (30 or 60 seconds) would increase frustration, and decrease task success and efficiency. They found that users were less frustrated with the one-second delay, but their task success and efficiency were not affected by either the 30 or 60 second response times.

Acceptable wait times:

One of the best recent series of studies was conducted by Anna Bouch (University College - London), Allan Kuchinsky and Nina Bhatti (Hewlett Packard Labs - Palo Alto). They attempted to identify how long users would wait for pages to load.

Users were presented with Web pages that had predetermined delays ranging from 2 to 73 seconds. While performing the task, users rated the latency (delay) for each page they accessed as high, average or poor. Latency was defined as the delay between a request for a Web page, and totally receiving that page.

They reported the following ratings
High (good): Up to 5 seconds
Average: From 6 to 10 seconds
Low (poor): Over 10 seconds

In a second study, when users experienced a page loading delay that was unacceptable, they pressed a button labeled "Increase Quality." The overall average time before pressing the "Increase Quality" button was 8.6 seconds.

In a third study, they had the Web pages load incrementally with the banner first, text next and graphics last. Under these conditions, users were much more tolerant of longer latencies. The test subjects rated the delay as "good" with latencies up to 39 seconds, and "poor" for those over 56 seconds.

Negative impressions:

Negative impressions of a website, that seem to have little to do with waiting, may be related to how long users must wait for pages to download. Ramsay, Barbesi and Preece (1998) examined the effect of page loading delays on users' perceptions of websites. Their delays ranged from two seconds to two minutes. Users rated pages on "interesting content," and the difficulty with which the page could be scanned. They found that pages with longer delays (41 seconds or longer) were rated as less interesting and more difficult to scan. In another study, participants felt that the slow loading of Web pages suggested that

  1. products being sold were of inferior quality, and
  2. the security of their purchases may be compromised.


Even after years of research, the complex relationship between computer response time and user performance and satisfaction is not totally clear. It seems that acceptable downloading times can range from five to over 30 seconds. The delays that are "acceptable" seem to depend on what tasks users re performing, and the difficulties they believe the computer is encountering. For example, users will tolerate only short delays if they believe that the task should be quick and easy for the computer.

Slow computer response times:

  1. may reduce the amount of work that users can do,
  2. probably have little practical effect on errors, and
  3. can be frustrating.

As users interact more with a website their frustration with downloading delays seems to accumulate. In general, the longer users interact with a site, the less delay they will tolerate.


Bailey, R.W. (1982), Human Performance Engineering (1st Edition), Prentice-Hall: Englewood Cliffs, NJ.

Bouch, A., Kuchinsky, A. and Bhatti, N. (2000), Quality is in the eye of the beholder: Meeting users' requirements for Internet quality of service, CHI 2000, 297-304.

Miller, R. B. (1968), Response time in user-system conversational transactions, In Proceedings of the AFIPS Fall Joint Computer Conference, 33, 267-277.

Martin, G.L. and Corl, K.G. (1986), System response time effects on user productivity, Behaviour and Information Technology, 5(1), 3-13.

Ramsay, J., Barbesi, A. and Preece, J. (1998), A psychological investigation of long retrieval times on the World Wide Web, Interacting with Computers, 10, 77-86.

Selvidge, P.R., Chaparro, B. and Bender, G.T. (2000), The world wide wait: Effects of delays on user performance, Proceedings of the IEA 2000/HFES 2000 Congress, 1-416-1-419.

Shneiderman, B. (1984), Response time and display rate in human performance with computers, Computing Surveys, 16, 265-285.

Message from the CEO, Dr. Eric Schaffer — The Pragmatic Ergonomist

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Privacy policy

Reviewed: 18 Mar 2014

This Privacy Policy governs the manner in which Human Factors International, Inc., an Iowa corporation (“HFI”) collects, uses, maintains and discloses information collected from users (each, a “User”) of its website and any derivative or affiliated websites on which this Privacy Policy is posted (collectively, the “Website”). HFI reserves the right, at its discretion, to change, modify, add or remove portions of this Privacy Policy at any time by posting such changes to this page. You understand that you have the affirmative obligation to check this Privacy Policy periodically for changes, and you hereby agree to periodically review this Privacy Policy for such changes. The continued use of the Website following the posting of changes to this Privacy Policy constitutes an acceptance of those changes.


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In the course of its business, HFI may perform expert reviews, usability testing, and other consulting work where personal privacy is a concern. HFI believes in the importance of protecting personal information, and may use measures to provide this protection, including, but not limited to, using consent forms for participants or “dummy” test data.

The Information HFI Collects

Users browsing the Website without registering an account or affirmatively providing personally identifiable information to HFI do so anonymously. Otherwise, HFI may collect personally identifiable information from Users in a variety of ways. Personally identifiable information may include, without limitation, (i)contact data (such as a User’s name, mailing and e-mail addresses, and phone number); (ii)demographic data (such as a User’s zip code, age and income); (iii) financial information collected to process purchases made from HFI via the Website or otherwise (such as credit card, debit card or other payment information); (iv) other information requested during the account registration process; and (v) other information requested by our service vendors in order to provide their services. If a User communicates with HFI by e-mail or otherwise, posts messages to any forums, completes online forms, surveys or entries or otherwise interacts with or uses the features on the Website, any information provided in such communications may be collected by HFI. HFI may also collect information about how Users use the Website, for example, by tracking the number of unique views received by the pages of the Website, or the domains and IP addresses from which Users originate. While not all of the information that HFI collects from Users is personally identifiable, it may be associated with personally identifiable information that Users provide HFI through the Website or otherwise. HFI may provide ways that the User can opt out of receiving certain information from HFI. If the User opts out of certain services, User information may still be collected for those services to which the User elects to subscribe. For those elected services, this Privacy Policy will apply.

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HFI may use personally identifiable information collected through the Website for the specific purposes for which the information was collected, to process purchases and sales of products or services offered via the Website if any, to contact Users regarding products and services offered by HFI, its parent, subsidiary and other related companies in order to otherwise to enhance Users’ experience with HFI. HFI may also use information collected through the Website for research regarding the effectiveness of the Website and the business planning, marketing, advertising and sales efforts of HFI. HFI does not sell any User information under any circumstances.

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HFI may disclose personally identifiable information collected from Users to its parent, subsidiary and other related companies to use the information for the purposes outlined above, as necessary to provide the services offered by HFI and to provide the Website itself, and for the specific purposes for which the information was collected. HFI may disclose personally identifiable information at the request of law enforcement or governmental agencies or in response to subpoenas, court orders or other legal process, to establish, protect or exercise HFI’s legal or other rights or to defend against a legal claim or as otherwise required or allowed by law. HFI may disclose personally identifiable information in order to protect the rights, property or safety of a User or any other person. HFI may disclose personally identifiable information to investigate or prevent a violation by User of any contractual or other relationship with HFI or the perpetration of any illegal or harmful activity. HFI may also disclose aggregate, anonymous data based on information collected from Users to investors and potential partners. Finally, HFI may disclose or transfer personally identifiable information collected from Users in connection with or in contemplation of a sale of its assets or business or a merger, consolidation or other reorganization of its business.

Personal Information as Provided by User

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Correcting, Updating, Accessing or Removing Personal Information

If a User’s personally identifiable information changes, or if a User no longer desires to receive non-account specific information from HFI, HFI will endeavor to provide a way to correct, update and/or remove that User’s previously-provided personal data. This can be done by emailing a request to HFI at Additionally, you may request access to the personally identifiable information as collected by HFI by sending a request to HFI as set forth above. Please note that in certain circumstances, HFI may not be able to completely remove a User’s information from its systems. For example, HFI may retain a User’s personal information for legitimate business purposes, if it may be necessary to prevent fraud or future abuse, for account recovery purposes, if required by law or as retained in HFI’s data backup systems or cached or archived pages. All retained personally identifiable information will continue to be subject to the terms of the Privacy Policy to which the User has previously agreed.

Contacting HFI

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PO Box 2020
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Terms and Conditions for Public Training Courses

Reviewed: 18 Mar 2014

Cancellation of Course by HFI

HFI reserves the right to cancel any course up to 14 (fourteen) days prior to the first day of the course. Registrants will be promptly notified and will receive a full refund or be transferred to the equivalent class of their choice within a 12-month period. HFI is not responsible for travel expenses or any costs that may be incurred as a result of cancellations.

Cancellation of Course by Participants (All regions except India)

$100 processing fee if cancelling within two weeks of course start date.

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4 Pack + Exam registration: Rs. 10,000 per participant processing fee (to be paid by the participant) if cancelling or transferring the course (4 Pack-CUA/CXA) registration before three weeks from the course start date. No refund or carry forward of the course fees if cancelling or transferring the course registration within three weeks before the course start date.

Cancellation / Transfer by Participants (Online Courses)

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Individual Modules: Rs. 3,000 per participant ‘per module’ processing fee (to be paid by the participant) if cancelling or transferring the course (any Individual HFI course) registration before three weeks from the course start date. No refund or carry forward of the course fees if cancelling or transferring the course registration within three weeks before the course start date.

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