In the previous chapter, we discussed some basic facts about eye movements. We then examined the amount of information that was extracted from a fixation and how this information was combined across fixations. The two major conclusions that emerged are that the reader can process somewhat more than the fixated word on a fixation and that some words are processed on more than one fixation. But our picture of eye movements is incomplete; we have said little about the time course of what is happening from fixation to fixation during reading. When we discussed basic facts of eye movements, we indicated, for example, that the reading rate, average fixation duration, and average saccade length all varied with different kinds of texts. Yet we said little about how the differences in the text change these variables. That is, for more difficult text we know that reading rate slows down, the average fixation duration increases, the average saccade size decreases, and the number of regressions increase. However, we have not discussed what, on a given fixation, causes the fixation to be longer, the following saccade shorter, or a regression to be made. Similarly, we know how much information is acquired on a fixation, but we have only touched upon the time course of the acquisition of this information.