In the foregoing experiment, the students improved in accuracy also. At the beginning of the work, they made 115 errors in the half hour. At the end of the practice, with much faster speed, they were making only 327 errors in a half hour. The actual number of errors had increased 280 per cent. The increase in errors was therefore exactly half as much as the increase in speed. This, of course, was a considerable increase in accuracy, for while the speed had increased to 5.6 times what it had been at the beginning, the errors had increased only 2.8 times. The subjects in this experiment paid much more attention to speed than they did to accuracy. If they had emphasized accuracy, they would have been doing almost perfect work at the end of the practice, and their speed would have been somewhat less. Practice, then, not only develops speed but also develops accuracy. There are also other results. At the beginning of work with the typewriter, there is much waste of energy and much fatigue. The waste of energy comes from using unnecessary muscles, and the fatigue is partly due to this waste of energy. But even apart from this waste of energy, an habituated act is performed with less fatigue. The various muscles concerned become better able to do their work. As a result of habituation there is, then, greater speed, greater accuracy, less waste of energy, and less fatigue. If we look not at the changes in our work but at the changes in ourselves, the changes in our minds due to the formation of habits, we find still other results. At the beginning of practice with the typewriter, the learner's whole attention is occupied with the work. When one is learning to do a new trick, the attention cannot be divided. The whole mind must be devoted to the work. But after one has practiced for several weeks, one can operate the typewriter while thinking about something else. We say that the habituated act sinks to a lower level of consciousness, meaning that as a habit becomes more and more fixed, less and less attention is devoted to the acts concerned. Increased skill gives us pleasure and also gives us confidence in our ability to do the thing. Corresponding to this inner confidence is outer certainty. There is greater objective certainty in our performance and a corresponding inner confidence. By objective certainty, we mean that a person watching our performance, becomes more and more sure of our ability to perform, and we ourselves feel confidence in our power of achievement.