Make it obvious what's clickable
Since a large part of what people are doing on the Web is looking for the next thing to click, it's important to make it obvious what's clickable and what's not.
For example, on Senator Orrin Hatch's Home page3 during his unsuccessful 2000 presidential bid, it wasn't clear whether everything was click-able, or nothing was. There were 18 links on the page, but only two of them invited you to click by their appearance: a large button labeled "Click here to contribute!" and an underlined text link ("full story"). (Figure 8)
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The rest of the links were colored text. But the problem was that all of the text on the page was in color, so there was no way to distinguish the links at a glance.
It's not a disastrous flaw. I'm sure it didn't take most users long to just start clicking on things. But when you force users to think about something that should be mindless like what's clickable, you're squandering the limited reservoir of patience and goodwill that each user brings to a new site.
One of my other favorite examples is the search box at drkoop.com (C. Everett Koop's health site).
Every time I use it, it makes me think, because the button that executes the search just doesn't look like a button—in spite of the fact that it has two terrific visual cues: It contains the word "search," which is one of the two perfect labels for a search box button,4 and it's the only thing near the search box. (Figure 9)
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It even has a little triangular arrow graphic, which is one of the Web's conventional "Click here" indicators. But the arrow is pointing away from the text, as though it's pointing at something else, while the convention calls for it to be pointing toward the clickable text. (Figure 10)
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Moving the arrow to the left would be enough to get rid of the question mark over my head.
Orrin Hatch deserves at least a footnote in usability history, since he was—to the best of my knowledge—the first presidential candidate to make Web usability a campaign issue. In the first televised Republican candidates' debate of the 2000 campaign, he told George W. Bush, "I have to say, Governor, in contrast to [your Web site], it's easy to find everything on mine. [Chuckles.] It's pretty tough to use yours! Yours is not user-friendly." (His site was easier to use.)
"Go" is the other one, but only if you also use the word "Search" as a label for the box.