We know now from a very elegant experiment (search for “Attention Web Designers: You Have 50 Milliseconds to Make a Good First Impression!”) that a lot happens as soon as you open a page. For instance, you take a quick look around (in milliseconds) and form a number of general impressions: Does it look good? Is there a lot of content or a little? Are there clear regions of the page? Which ones attract you? The most interesting thing about the experiment was that they showed that these initial impressions tended to be very similar to the impressions people had after they actually had a chance to spend time on the page. In other words, we make snap judgments, but they tend to be a pretty reliable predictor of our more reasoned assessments.1211 ↱
Don't Make Me Think, Revisited
A Common Sense Approach to Web Usability
Steve Krug