31 May 2007

Don't Make Me Think

Here's a couple of snippets from Steve Krug's Don't Make Me Think: A Common Sense Approach to Web Usability. He makes some points that are pretty obvious, but easy to overlook.
Pulldowns are most effective for alphabetized lists of items with known names, like countries, states, or products, because there's no thought involved. If I'm looking for VCRs, for instance, I can just scroll down to the V's.

But they're much less effective for lists where I don't lnow the name of the thing I'm looking for, especially if the list isn't alphabetized or is long enough to require scrolling. (p. 110)

...the Web experience is missing many of the cues we've relied on all our lives to negotiate spaces. Consider these oddities of Web space:

No sense of scale. Even after we've used a Web site extensively, unless it's a very small site we tend to have very little sense of how big it is (50 pages? 1,000? 17,000?). For all we know, there could be huge corners we've never explored. Compare this to a magazine, a museum, or a department store, where you always have at least a rough sense of the seen/unseen ratio.

The practical result if that it's very hard to know whether you've seen everything of interest in a site, which means it's hard to know when to stop looking.

This is one reason why it's useful for links that we've already clicked on to display in a different color. It gives us some small sense of how much ground we've covered. (p. 57 and note)

Imagine a browser extension that lets you specify how soon to revert links to the univisited color on a per-domain basis, instead of the global setting that Internet Explorer and Firefox provide. I would be all over that.

21 May 2007

Plot this

Check out FooPlot, an online graphing calculator. If I'd had this 35 years ago, I might have really understood polar coordinates.

(Via Compiler.)

Mystery solved?

I may have figured out the intermittent problem that manifested itself with the error message:

The file web.sitemap required by XmlSiteMapProvider does not exist.

It turns out that the web server on my development box was configured to allow anonymous access, with the "Internet Guest Account" identified as the proxy account. This is the account named IUSR_<server name>. Fairly standard set-up.

What we changed, what seems to have dealt with the problem, is to specifically grant permissions to IUSR_<server name> to the file system folder that the virtual directory was mapped to. From Windows Explorer, context-click the folder, pick Properties, then pick the Security tab. Because the web app writes log files under that folder, and the web site admin can also use the app to add and delete uploaded files (themes, templates, that sort of thing) under that folder, we granted Full Control to the Internet Guest Account.

YMMV. Reflecting on this, it occurs to me that it's probably not the best choice from a security point of view to allow the web app this degree of access. Config parameters that point to the log files and templates and themes would be a good idea: I will bring it up with the team.

Tap tap-tap

Jim Horning has started a thread on the Risks Digest about slow keyboard response in Internet Explorer 7, apparently when lots of JavaScript has been executed in the browser window's lifetime. Multiple tabs exacerbate the problem.

04 May 2007

Still collating

Douglas W. Jones, on the CS faculty of the University of Iowa, maintains an online museum of punchcards (originally known as Hollerith cards) and related technology.

(Link via things magazine.)