Sep 19 - Nielsen, How Little Do Users Read? (Alertbox)

How Little Do Users Read?

Summary: On the average Web page, users have time to read at most 28% of the words during an average visit; 20% is more likely.


We've known since our first studies of how users read on the Web that they typically don't read very much. Scanning text is an extremely common behavior for higher-literacy users; our recent eyetracking studies further validate this finding.

Among other things, the authors found that the Back button is now only the 3rd most-used feature on the Web. Clicking hypertext links remains the most-used feature, but clicking buttons (on the page) has now overtaken Back to become the second-most used feature. The reason for this change is the increased prevalence of applications and feature-rich Web pages that require users to click page buttons to access their functionality.
Of course, Back is still the user's lifeline and is so frequently used that supporting it remains a strong usability guideline.

Obviously, users tend to spend more time on pages with more information. However, the best-fit formula tells us that they spend only 4.4 seconds more for each additional 100 words.
Usually, I assume a reading speed of 200 words per minute (WPM), but because the users in this study are highly literate, I'll go with 250 WPM. At that reading speed, users can read 18 words in 4.4 seconds. Thus, when you add verbiage to a page, you can assume that customers will read 18% of it.

The formula seems to indicate that people spend some of their time understanding the page layout and navigation features, as well as looking at the images. Clearly, people don't read during every single second of a page visit.
However, the total time spent on a page is definitely the upper limit of possible reading time. Thus, we can calculate the hypothetical maximum number of words users would be able to read, if they allocated their entire page-visit to reading.

On an average visit, users read half the information only on those pages with 111 words or less.

In the full dataset, the average page view contained 593 words. So, on average, users will have time to read 28% of the words if they devote all of their time to reading. More realistically, users will read about 20% of the text on the average page.


source:
Jakob Nielsen's Alertbox, May 6, 2008:
How Little Do Users Read?
http://www.useit.com/alertbox/percent-text-read.html
How Little Do Users Read? (Jakob Nielsen's Alertbox)