Identifying Important Operating Systems

Essays in this series about understanding your audience:

Visitors to your site will be using any of a number of operating systems on their computers (or computing systems, platforms, appliances, etc.). For any large commerce site, making the assumption that the audience will be using the same operating system that the design team is using is guaranteed to cause problems for some users, because your audience won't be homogeneous, and some users will be excluded because their operating system doesn't handle your site appropriately.

You need to understand which operating systems are most likely to be used by the majority of your visitors, because

operating system choice is an important bit of demographic data about your users;
different operating systems support visual interfaces differently, so browsers will render and display your pages differently;
different operating systems will have varying levels of support for some Internet functionalities, such as cookies, JavaScript, etc.

At the very least, a strong understanding of operating systems will put you in a position of understanding how non-supported operating systems will fail when accessing your site.

Information on operating systems and their relative popularity is available from various kinds of sources, including web sites, magazine articles, books, and surveys. I suggest the following basic process as forming a good framework on which to base an ongoing understanding of operating systems. Your final result should be a list of operating systems that are identifiable as important to your users, and therefore important for your programmers, designers, and site architects to accommodate.

1. Find out what's commonly available

The first step in your research is to find out what operating systems are in common use. The easiest way to do this is to visit several web sites that record user statistics such as operating systems, browsers and platforms used by visitors; these sites usually record and number-crunch statistics for visitors to a group or network of sites. The advantages of these statistic-tracking sites is that they have done the dirty work of collecting and collating the raw data: you can simply examine their data and start building your conclusions.

Statmarket.com

The current leader in statistical information about users and their systems is StatMarket.com. This site provides snazzy charts for at-a-glance comparisons, but I'd still prefer some tabular data so I can do my own comparisons using the raw data. The following table shows operating system statistics across a three-month period, ranked by popularity; the raw statistics came from StatMarket.com's 3-month views as generated on May 24, 1999.

TABLE 1: Operating System Statistics from StatMarket.com, ranked by average popularity
Rank	OS	Avg.	Min. (Date)	Max. (Date)
1.	Windows 95	48.28%	41.93% (5/23/99)	54.23% (1/8/99)
2.	Windows 98	39.80%	33.29% (1/8/99)	48.17% (5/17/99)
3.	Windows NT	4.81%	2.86% (1/17/99)	6.40% (5/21/99)
4.	Macintosh	2.72%	2.40% (1/17/99)	3.04% (1/27/99)
5.	WebTV	1.81%	1.52% (3/17/99)	2.23% (1/13/99)
6.	Windows 3.*	1.38%	1.04% (5/23/99)	1.80% (1/13/99)
7.	Other	0.56%	0.09% (2/22/99)	0.69% (5/17/99)
8.	Linux	0.20%	0.16% (1/9/99)	0.22% (5/22/99)
9.	SunOS	0.16%	0.08% (5/10/99)	0.23% (2/19/99)
10.	Irix	0.04%	0.01% (3/2/99)	0.06% (2/24/99)

2. Analyze Your General Statistics

Once you have data on the most popular operating systems, as reflected by general-purpose statistics, you need to do some thinking about these stats.

First, look at your statistics and figure out which different listings actually refer to the same operating system, and combine the data where appropriate. For example, my guess is that Windows 3.1 and Win16 are the same thing, and Windows 95 and Win95 are likewise the same. If your figures for the same operating system are significantly different across the different sets of data you're using, find the average. If you have statistics that don't make any sense, discard them.

Second, you should decide which operating systems are important enough - based on these general statistics - to be considered in your design and quality assurance process. Pick a threshold of popularity, and rank the operating systems that fall above that threshold. For example, say you set a threshold of 1%; this means that every operating system that generally ranks above 1% is an operating system important enough for you to incorporate and consider in your site's design and testing process. This yields the following table showing Statmarket's average figures on the left and BrowserStat's February figures on the right.

TABLE 2: Browsers that have more than 1% recorded usage
Windows 95	48.28%	Windows 95	55.85%
Windows 98	39.80%	Windows 98	22.41%
Windows NT	4.81%	Windows NT	9.32%
Macintosh	2.72%	Macintosh Power PC	4.11%
Windows 3*	1.38%	Windows 3.* (Win16)	2.33%
WebTV	1.81%	WebTV	1.07%

Third, track these statistics over time. You need to be able to identify trends before your audience changes significantly. If an operating system gains enough popularity to boost it onto your "radar screen", you need to consider that your audience may start reflecting the same acceptance of that OS, so your site had best accommodate work with it.

3. Monitor The Media

Keep abreast of current news about operating systems, and the popularity and media attention paid to any particular operating system. When a new operating system - or an upgrade to an existing operating system - is released, you have to be ready to evaluate that operating systems' relevance to your audience. If your typical user works with Windows 95, and Microsoft releases, and hypes, a new OS called Windows 98, then you have to consider how your site will function on Windows 98.

Any operating system that becomes a media darling, for example Linux, deserves your attention as well. With all the intense attention on Linux, this operating system has yet to register as even a quarter of 1 percent in any of the general statistics I've seen, yet I know that this is an important OS.

My predictions?

Watch Linux, or course, because of the dissatisfaction with Microsoft's OS products. Once Linux gets a smoother Windows manager and traditional office-type applications, Linux should take off.
Watch WebTV, which is growing in popularity among non-computer users. WebTV is especially popular among older web surfers.
Watch PalmOS, because as soon as the new wireless Palm models become widely available and used, and as the palm network becomes better architected, we should see a great deal more web visitors using Palms.
I'm curious about BeOS. I keep reading about it, but still read no major push for its adoption. Here's a good BeOS article written by Scott Hacker for Byte magazine.

4. Look at Your Site's Logs

Your server's user-agent logs can tell you a great deal about the operating systems used by your visitors. All the web sites that provide browser and operating system statistics are simply number crunching the information from their logs and presenting them in a pretty format. Write some simple scripts of your own to generate meaningful reports from your logs.

I've prettied up the user-agent log from philosophe.com to show the amazing range of agents that will access even such a small and specialized site as philosophe.com. Just a quick look at this log should give you an idea about the main range of operating systems accessing the site.

5. Make Some Judgments

Once you've gathered and looked at operating system data, you can make some well-founded assumptions and judgments about your site's audience, and their operating system usage. These judgments should in turn inform your site's design and testing processes.

Windows 95: By far the most popular OS.
Windows 98: The most popular OS after Windows 95, and quickly gaining market share.
Windows NT: The most popular OS after Windows 98.
Macintosh PowerPC: The most popular non-Windows OS .
Linux: By different measurements, all flavors of UNIX as a group cover as little as less than 1 percent of users; Linux, however, is becoming increasing prominent. I consider Linux to be more important that Windows 3.1 as far as testing is concerned. The problem with Linux, however, is that you can't predict which Windows manager users will favor.
Windows 3.1: The fifth most popular operating system; even though its numbers can only decline, it still has more users -- apparently -- than does Linux.

6. Improve Your Quality Processes

Now that you have this information on operating systems, use it to improve your design and testing processes. If your specialized customer-base tends to favor an operating system that is not one of the most common, start including that OS in your design considerations. If you find some surprises in just which operating systems are common to your audience, re-explore your understanding of your audience.

Once you have a grip on the common operating systems, use that information to create a set of test machines that run the relevant operating systems.

People who surf the web are known to be fickle: with so many options and multiple choices for any particular kind of a site or source of content, any frustration encountered by a user is often a ticket out of a site forever. Ensuring a quality user experience calls for a constant evaluation of the user experience and constant research into the makeup and characteristics of your audience. The nature of the web changes at least slightly each time an operating system is released or upgraded. Everything I've discussed in this essay is stuff that you should pay attention to on an ongoing basis. Be proactive when it comes to understanding what your audience uses to access your site.

[ Read the next essay in this series about understanding your audience, Identifying Important Browsers.]