264 REPORTS ON THE STATE OF SCIENCE, ETC. 
VOCATIONAL TESTS AND ABILITIES. 
Report of Committee appointed to develop tests of the routine manual factor 
in mechanical ability (Dr. C. S. Myers, C.B.E., F.R.S., Chairman ; 
Dr. G. H. Mies, Secretary; Prof. C. Burt, Dr. F. M. EARLE, 
Dr. Lt. Wynn JONES, Bro. 1. ti. PEAR): 
Work has progressed along the following lines as laid down in last year’s 
(final) report of the Committee appointed to inquire into the factors involved 
in mechanical ability : 
(1) The development of new manual tests with a view to simplifying and 
improving the measurement of the manual factor in assembly work. 
(2) The devising of new methods of administering the tests of mechanical 
aptitude, with a similar aim in view. 
(3) The development of easier tests of mechanical aptitude with a view 
to its measurement in elementary school children. 
(4) The devising of new tests of mechanical aptitude with a view to the 
further analysis of the mechanical factor. 
Data have been collected from the top two classes of an elementary school 
and from six forms of a junior technical school. Its statistical analysis is 
in progress. 
It is hoped that the Association will continue to support the work along 
the lines suggested in Part III of this report,-by renewing, and if possible 
increasing, its financial grant. 
J. THE POSITION AT THE BEGINNING OF THE YEAR. 
The results reported to the Association up to the beginning of the year 
may be briefly stated as follows : 
(a) The factors involved in assembling work.—Ability at the assembling 
operations investigated depends on two or more of the following factors, 
according to the particular operation : 
(1) A small general factor (‘ intelligence ’), which is more evident in the 
mechanical assembling tests, and in the more complex of the routine assem- 
bling operations, and which tends to disappear from the less complex routine 
assembling operations and from simple tests of manual dexterity. 
(2) A ‘ mechanical ’ factor, identified with the ‘ m ’ factor in non-manual 
tests of mechanical aptitude, which is most conspicuous in the mechanical 
assembling tests, which tends to enter to a small extent into the more com- 
plex of the routine assembling operations, and which tends to disappear 
from the simpler of these operations. 
(3) A ‘manual’ factor, which enters most conspicuously into the more 
complex of the routine assembling operations, to an obvious, though less, 
extent into the less complex of these operations and into the simple manual 
tests, and which tends to disappear, as a group factor, from the mechanical 
assembling tests. 
(4) A factor specific to each operation, which plays a larger part in the 
simpler operations, and diminishes in importance as the operation becomes 
more complex. 
(b) The measurement of the factors—(1) The mechanical factor is best 
measured by the non-manual tests of mechanical aptitude. Of the mechani- 
cal assembling tests, the more difficult ones provide the better measure. 
