In order to help in evaluating the efficiency of eLocutor in helping you type, the bottom right of the screen shows two numbers (see Figure 30-2). These indicate the number of clicks and the number of seconds between the last click and the first, since the middle box was last empty.
We found that when the prediction worked reasonably well, the ratio of clicks to characters typed was better than 0.8—i.e., it usually required significantly fewer clicks than an able-bodied person would have needed using a full keyboard. When prediction was poor—for instance when constructing a sentence radically different from any in the database—it required up to twice as many clicks as characters typed.