Alertbox: How Many Test Users in a Usability Study?

Jakob Nielsen <[email protected]> Mon, 4 Jun 2012 12:30:39 -0400
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The answer is 5, except when it's not. Most arguments for using more
     test participants are wrong, but some tests should be bigger and
     some smaller.
     > http://www.useit.com/alertbox/number-of-test-users.html

    Jakob Nielsen's Alertbox for June 4: How Many Test Users in a
     Usability Study?
     __________________________________________________________________

Usability Week 2012 conference

     * Chicago: June 25-29
     * Toronto: July 23-27
     * Sydney: August 12-17
     * San Francisco: September 23-28
     * London: October 14-19

   Full event program describing all full-day training courses.
   > http://www.nngroup.com/events
__________________________________________________________________

Intranet Design Competition

   The annual design competition to identify the world's 10 best intranets
   is now open.

   Call for Entries: Deadline June 27
   > http://www.nngroup.com/reports/intranet/2013
     __________________________________________________________________

Windows Phone User Testing

   We recently conducted some usability research with Windows Phone in
   Amsterdam. (Doing this research in Europe because Nokia is much more
   popular there than in the U.S.) I was pleasantly surprised. The live
   tiles worked well, and user reactions to the phone were positive.

   On the other hand, task performance using actual websites was less
   positive.

   Our sample size was too small to conclusively state whether current
   mobile sites work better or worse on Windows Phone than on other
   popular phones. All I can say at this time is that you should consider
   testing your mobile site with Windows Phone users if you expect this
   platform to be important for you.

   We will probably have more to say later, after the new version of
   Windows Phone ships and we've tested it with more users in more
   countries.
     __________________________________________________________________

Russia: the New Web Power

   The latest data on Internet growth in Europe shows that Russia now
   has the largest number of users, surpassing earlier-adopters like
   Germany and the U.K.
   > http://www.economist.com/node/21555560

   At the recent Usability Week conference in Amsterdam, Russia was the
   country sending the most participants after the host country
   (Netherlands) and its two neighboring countries (Germany and Belgium).

   Also, across the full year of Usability Week events, we now have a
   Russian company represented on the list of most-attending companies:
   Odnoklassniki (a social network that's bigger than Facebook in Russia).
   I believe this is the first time a company from Eastern Europe has made
   this exclusive list of organizations that invest heavily in
   usability.

   In total, usability enthusiasts from 32 countries attended our
   Amsterdam conference.
     __________________________________________________________________

Drive Safely

   The Network of Employers for Traffic Safety has a lot of good
   resources that may save your life or that of your colleagues or
   children, by encouraging them to reduce driver distraction.
   > http://trafficsafety.org
     __________________________________________________________________
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                                                            <div><div style="text-align: left">
	<blockquote style="padding-bottom: 4px; line-height: 130%; background-color: #ffffdd; margin: 0px; padding-left: 4px; padding-right: 4px; color: #000000; padding-top: 4px">
		<p style="margin-top: 0px; margin-bottom: 2px">
			<a href="http://useit.us4.list-manage.com/track/click?u=538d934a891681a5d850bb4e5&id=a0b1ae4787&e=f405d0f72c" style="color: #505050; text-decoration: none"><span style="color: #505050">Summary:</span><br>
			The answer is 5, except when it&#39;s not. Most arguments for using more test participants are wrong, but some tests should be bigger and some smaller.</a></p>
		<p style="line-height: 140%; margin-top: 4px; margin-bottom: 0px; font-size: 120%">
			<a href="http://useit.us4.list-manage1.com/track/click?u=538d934a891681a5d850bb4e5&id=1b5c1e60d3&e=f405d0f72c" style="color: #505050; text-decoration: none">Jakob Nielsen&#39;s Alertbox for June 4: <span style="color: #0033aa; text-decoration: underline"><strong>How Many Test Users in a Usability Study? </strong></span></a></p>
	</blockquote>
	<hr>
	<h3>
		Usability Week 2012 conference</h3>
	<ul>
		<li>
			<a href="http://useit.us4.list-manage.com/track/click?u=538d934a891681a5d850bb4e5&id=47d367deeb&e=f405d0f72c">Chicago</a>: June 25-29</li>
		<li>
			<a href="http://useit.us4.list-manage1.com/track/click?u=538d934a891681a5d850bb4e5&id=ffed9a3248&e=f405d0f72c">Toronto</a>: July 23-27</li>
		<li>
			<a href="http://useit.us4.list-manage.com/track/click?u=538d934a891681a5d850bb4e5&id=4bd39754db&e=f405d0f72c">Sydney</a>: August 12-17</li>
		<li>
			<a href="http://useit.us4.list-manage2.com/track/click?u=538d934a891681a5d850bb4e5&id=bbc789b6fe&e=f405d0f72c">San Francisco</a>: September 23-28</li>
		<li>
			<a href="http://useit.us4.list-manage2.com/track/click?u=538d934a891681a5d850bb4e5&id=7621dff795&e=f405d0f72c">London</a>: October 14-19</li>
	</ul>
	<p>
		<a href="http://useit.us4.list-manage.com/track/click?u=538d934a891681a5d850bb4e5&id=114d93f19b&e=f405d0f72c">Full event program</a> describing all full-day training courses.</p>
	<hr>
	<h3>
		Intranet Design Competition</h3>
	<p>
		The annual design competition to identify the <strong>world&#39;s 10 best intranets</strong> is now open.</p>
	<p>
		<a href="http://useit.us4.list-manage2.com/track/click?u=538d934a891681a5d850bb4e5&id=24da844f3a&e=f405d0f72c">Call for Entries</a>: Deadline June 27</p>
	<hr>
	<h3>
		Windows Phone User Testing</h3>
	<p>
		We recently conducted some usability research with Windows Phone in Amsterdam. (Doing this research in Europe because Nokia is much more popular there than in the U.S.) I was pleasantly surprised. The live tiles worked well, and user reactions to the phone were positive.</p>
	<p>
		On the other hand, task performance using actual websites was less positive.</p>
	<p>
		Our sample size was too small to conclusively state whether current mobile sites work better or worse on Windows Phone than on other popular phones. All I can say at this time is that you should consider testing your mobile site with Windows Phone users if you expect this platform to be important for you.</p>
	<p>
		We will probably have more to say later, after the new version of Windows Phone ships and we&#39;ve tested it with more users in more countries.</p>
	<p>
		<em>See also:</em> Nice (but looong) article on the <a href="http://useit.us4.list-manage.com/track/click?u=538d934a891681a5d850bb4e5&id=b7d5298762&e=f405d0f72c">interaction design concepts in Windows 8</a>.</p>
	<hr>
	<h3>
		Russia: the New Web Power</h3>
	<p>
		The latest data on <a href="http://useit.us4.list-manage2.com/track/click?u=538d934a891681a5d850bb4e5&id=bf88b79c2c&e=f405d0f72c">Internet growth in Europe</a> shows that Russia now has the largest number of users, surpassing earlier-adopters like Germany and the U.K.</p>
	<p>
		At the recent Usability Week conference in Amsterdam, Russia was the country sending the most participants after the host country (Netherlands) and its two neighboring countries (Germany and Belgium).</p>
	<p>
		Also, across the full year of Usability Week events, we now have a Russian company represented on the list of most-attending companies: Odnoklassniki (a social network that&#39;s bigger than Facebook in Russia). I believe this is the first time a company from Eastern Europe has made this exclusive <a href="http://useit.us4.list-manage.com/track/click?u=538d934a891681a5d850bb4e5&id=a6fdc83ce6&e=f405d0f72c">list of organizations that invest heavily in usability</a>.</p>
	<p>
		In total, usability enthusiasts from <strong>32 countries </strong>attended our Amsterdam conference.</p>
	<hr>
	<h3>
		Drive Safely</h3>
	<p>
		The <a href="http://useit.us4.list-manage.com/track/click?u=538d934a891681a5d850bb4e5&id=e70bf95f1b&e=f405d0f72c">Network of Employers for Traffic Safety</a> has a lot of good resources that may save your life or that of your colleagues or children, by encouraging them to reduce driver distraction.</p>
	<hr>
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