The author submits a survey of the basic results of an empirical investigation of the psychical performances of pupils of the 9th form of the Elementary Nine form School, made with a modified version of Bourdon’s crossing-out test. Two types of experiments were carried out. In experiment I 268 persons were given a test for the first time in the course of the first and repeatedly (after two weeks) in the course of the fifth lesson. In experimerit II 274 persons were given a test for the first time in the course of the fifth and repeatedly (after two weeks) in the course of the first lesson. Table 1 gives a survey of the basic statistical data on the performance, frequency of errors and frequency of corrections in both types of experiments. Table 2 gives the percentage of errors and corrections in the performance in the 1st to 6th five-minute time interval. Table 3 gives a percentual comparison of the performance, frequency of errors and corrections in the 1st to 6th five-minute time interval. Fig. 1 illustrates the distribution of the performance, errors and corrections in the performance in the 1st to 6th five-minute time interval. Fig. 2 illustrates the dynamics of the changes of the average performance of the boys and girls during the first and the repeated test. Fig. 3 and 4 illustrate the dynamics of the frequency of errors and frequency of corrections in the performance of the boys and girls during the first and the repeated test. The following most important results were obtained:
1. The differences in the quantity of the performance of the tested persons in the first and repeated test are statistically very significant.
2. The quantity of the performance in the first test is equivalent, regardless whether the test was given for the first time during the first or the fifth lesson.
3. The quantity of performance in the repeated test is equivalent, regardless whether the test was given during the fifth or first lesson.
4. A statistically very significant positive correlation was found between the quantity of performance during the first and the repeated test.
5. In the repeated test the quality of the performance of the tested persons increases, i. e. the percentage of errors and corrections decreases.
6. Great inter-individual differences in the performance and mainly in the quality of the tested persons were determined.
7. The distribution of the performance and the frequency of errors has a different character in the first and the repeated test.
8. The dynamics of the changes of the performance in the first and the repeated test has a significantly differing tendency.
9. Of decisive influence on the quantity and quality of the performance, but also on the character of the dynamics of the changes in the performance of the tested persons, was the order of the test and not the fact in the course of which lesson the test was given for the first time and in the course of which lesson it was repeated.