2. What correlation exists between mental and motor abilities?
3. Do the tests measure fundamental qualities or general powers of the individual, or specialized capacities, or perhaps mainly the effect of general or special training?
4. If they measure general qualities, which of the existing tests are the best for this purpose?
5. How many trials are needed to afford a reliable index of the individual's ability?
6. What are the principal incidental factors that influence the result of tests?
7. Which tests are most easily influenced or disturbed by extraneous factors?
8. Can tests of the simpler laboratory type be used to indicate the individual's ability as shown in his daily work and play?
9. How simple or complex should the various tests be in order to give the best results?
10. How many tests, and which, are required to give a fairly correct picture of the individual's psychological make-up?
11. To what degree do preliminary trials indicate the final capacity of an individual?