The Basics: How We Read
In understanding eyetracking results and data, it's helpful to understand the process of reading. People typically recognize words as a whole; we don't look at individual letters in each word.

According to psycholinguist Keith Rayner of the University of Massachusetts at Amherst, eyes do not move smoothly across the text as we read. Instead, the typical reader behavior is to look at a word or several words in a group, and pause our eyes there briefly. This is called a "fixation," and it takes about 0.25 seconds on average.

After a fixation, we move our eyes to the next word or group of words; this movement is called a "saccade" and takes only 0.1 seconds. (People often skip over short or predictable words such as "of," "in," "a," etc.) After this pattern is repeated once or twice, we pause to comprehend the phrase just viewed (which on average takes 0.3 to 0.5 seconds).

According to Rayner, all these fixations and saccades result in 95 percent of all college-level people reading between 200 and 400 words per minute; 300 words per minute is the average.

As you read about Eyetrack III findings on this website, you'll often see references to "fixations." A fixation is a brief, but measurable, pause of the eye when looking at a word or phrase. "Saccades" are the paths between these fixations