First Steps - Page 4

Appendix

The results of this test were submitted for review on the kde-usability mailing list. This appendix addresses some of the questions asked and comments made on the list.

Who were the test participants?

Test participants were between 20 and 55 years old with education levels ranging from high school diploma to PhD. All of them had in common at least 2 years of day-to-day experience with computers (read familiarity with Windows and MS Office for the most part). Only one had a background in Engineering/Computer Science. None of them had any meaningful experience with computing environments other than Windows.

How do we deal with bad inherited behavior?

Observations about single-clicking vs. double-clicking exposed deep differences of opinion on what it means to say that people are uncomfortable with a particular aspect of the interface. Some people expressed concern over making changes based on having observed test participants troubled with unfamiliar design derived from otherwise sound usability theory.

For instance, there aren't any compelling reasons to favor double-clicking over single-clicking on technical grounds. In fact, some argue that the opposite may be true. Aaron Siego cited Jef Raskin saying that "[t]he act of double clicking is, however, itself problematic. Double clicking requires operating a mouse button twice at the same location or at two locations in very close and, in most cases, within a short time, typically 500 msec. If the user clicks too slowly, the machine responds to two single clicks rather than to one double click. If the user jiggles the mouse excessively between clicks, the same error occurs. If the user taps the GID button twice in too short a time period, as when trying to select text within a word while working within certain word processors, the machine considers the two taps as a double click and select the whole word." (1). With this in mind, what should we do? On the one hand, test participants are familiar with double-clicking; on the other, KDE traditionally employs single-clicking and there are theoretical indications that it should be preferred. If we switch to double-clicking aren't we simply perpetuating bad habits and settling for mediocre interface design? If we chose single-clicking, aren't we ignoring users and favoring theory over practice?

My opinion is that we should follow the existing standard. People double-click so let's have KDE be double-clickable by default. Novices will most likely not care one way or the other. People switching to KDE from other systems will be at ease immediately. Power users will still have the option to revert back to single-clicking easily if they chose to. There is absolutely nothing to lose.

Some complain that this would make KDE too much like Windows when this has actually nothing to do with Windows. Whether people do what they do because of Windows, MacOS or Amiga is irrelevant. The only thing that matters is to make KDE behave in a way that makes sense to people and let them use their environment transparently. Now consider this: many applications from the free software community (Mozilla, the Gimp...) are in fact double-clickable. Making KDE a double-click environment will help integrating these essential pieces of software into KDE. That's yet another good reason to follow the current practice. Unless of course you're worried that KDE is becoming too much like Mozilla!

Another common argument in these debates is that favoring existing behavior stales KDE's ability to be innovative. This is also irrelevant when dealing with established behavior. Innovation is good where innovation is needed, or in Bruce Tognazzini's words "Invent new objects, with new appearances, for new behaviors." (2) There's plenty of room for creativity within KDE and many opportunities to show our smarts but we can't ask millions of people to ignore what they've been learning over the past twenty years just because we may have something that's better in principle. It doesn't work that way and it surely won't work when dealing with an aspect of the interface for which people show no discontent such as double-clicking. Here's what Don Norman has to say about this particular point: "It doesn't matter whether or not your technology is superior; it only matters that what is being offered is good enough for the purpose." (3) And, for good measure, Jakob Nielsen's opinion: "Only deviate from a design standard if your alternative design has at least 100% higher measured usability." (4) and (just substitute website for desktop environment) "Therefore, I recommend following the conventions even in thoses cases where a different design would be better if seen in isolation. The fact is, no website is seen in isolation: users come to your site expecting things to work the same way they are already used to." (4)

Now, can we move on?

Notes

1 Jef Raskin, "The Humane Interface: New Directions for Designing Interactive Systems" (Reading: Addison-Wesley, 2000)

2 Bruce Tognazzini, "Tog on Interface" (Reading: Addison-Wesley, 1992), p. 249

3 Donald A. Norman, "The Invisible Computer: Why Good Products Can Fail, the Personal Computer Is So Complex, and Information Appliances Are the Solution" (Cambridge: MIT Press, 1998). This book is great. I highly recommend it to anyone interested in software development and the usability aspects of it.

4 Jacob Nielsen, "When Bad Design Elements Become the Standard", "Jakob Nielsen's Alertbox" (November 1999)

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