The basic activity of the student during the "computer training process" is the introduction and processing of information. In the dialogue regime of work, between student and computer, the velocity and accuracy of the information processing take important place. In this aspect, special attention is given to the changes in the indicated indices during the computer lesson, computer plays and the traditional training. Studies are carried out on 30 students from classes X and XI, educated in vocational school "V. Levski", the town of Pravets. For the purpose is used electron determinator with test programme, containing consecutively exposure to 50 visual stimulators in red, blue, green, yellow and white colours at 1,2 s/speed. The results as a whole show that the most favourable results concerning the computer plays, very likely could be explained with the diversion effect and the positive motivation adjustment to the activity performed. By means of dispersion analysis is established, that only the type of activity has an essential effect on the velocity and accuracy of the information processing.