I suppose there is an endless supply of people passing unsubstantiated personal opinion as established fact, especially online. Kathy Sierra’s recent post (see below) is but one example of this epidemic corrosion of knowledge. Kevin O’Keefe at Lexblog gives us another example. Of course he isn’t just some pusher of high-fructose-corn-feel-goodness—he’s a former trial lawyer, someone who’s job it is to distinguish fact from opinion. Yet he says:

LexBlog still gets clients saying they want all links on their blogs to open a new window. Why? Because they fear people will leave their blog. Is that nuts or what?

Want to tick people off? Have your links open new windows. Have users click to a number of links on your blog so they now have 8 or 9 windows open. Make it difficult to browse because the back button can’t be used to browse because every link is a new window. You’ll have people unsubscribing from your blog in a New York minute.

So after overstepping the bounds of his expertise from law to usability, what evidence does he provide? None. His opinion on usability and surfing practices is fact because he says so. Well, opinion is not fact, especially when your opinion is wrong: I’ve experienced (and I do have expertise in this matter) in formal testing the exact opposite of what Kevin says. Browser users do not surf sequentially, but do so in parallel—a behaviour better supported by links that spawn new windows than links that reuse the same window.

So what’s the big deal? Clearly it isn’t the Lexblog post. Its that as we loose both respect for and familiarity with actual evidence in a flood of personal opinion passed off as fact, discourse quickly becomes little more enlightening than a Crossfire style shouting match—and that’s where progress stops.

Unfortunately I’ve found that desgin discource is particularly prone to this.