Speed and precision in manual skill / by D.F. Vincent.

  • Vincent, D. F.
Date:
1955
Catalogue details

Licence: In copyright

Credit: Speed and precision in manual skill / by D.F. Vincent. Source: Wellcome Collection.

    11/28 (page 5)
    pegs are of hard plastic, two inches long and three sixteenths of an inch in diameter. A peg-board is a versatile piece of apparatus and can form the basis of a variety of manipulative tests. In this study the upper fifty holes of the board were filled with pegs and the task was to move them one by one to the lower fifty holes. To make the task a little more difficult it was required that each peg should be turned upside down before being placed in one of the lower holes. The scoring was by the time in seconds to per¬ form this task. The final score was the total time required for five runs. Cox Eye-board. The third test used was the (J.W.) Cox Eye-board. In this test there are ten laces fastened at one end to the board and with a tag at the other. Each lace has to be threaded suc¬ cessively through a row of twenty screw-eyes. It requires rather more complicated manipulation with the fingers than the other two tests of this group. In this case, each run consisted of thread¬ ing two of the laces. The scoring was by the time in seconds for each run. The final score was the total time required for five runs. THE ‘ PRECISION-DEXTERITY ’ GROUP OF TESTS There were no suitable tests in existence and a certain amount of experimental work had to be done to devise tests. The Tracking Tests. The aim was to produce a test that would present a difficult manipulative task to be performed with one hand. The general idea was to perform some operation on a small object with an implement arranged so that a small move¬ ment at the manipulating end produced a large movement at the operating end. For the task we used a cylinder of brass three-eighths of an inch high and half-an-inch diameter, which had to be pushed along the top of a miniature wall, without being knocked off. In the preliminary experimental work, we used three types of miniature wall. One was of a zig-zag formation with a uniform width of a quarter of an inch. Another was an hexag¬ onal spiral, also of a uniform width of a quarter of an inch. The third, the one finally adopted, was in the form of a true spiral of three turns, four inches external diameter, and with the wall vary¬ ing in width from a quarter of an inch at the out¬ side to one eighth of an inch at the inside. The wall was marked off into sections radially and the scoring was by the number of sections over which the cylinder was pushed before it was knocked off. A considerable amount of experimental work was necessary before a suitable device for pushing the cylinder along the wall was found. The first two devices were discarded because they were found to be too complicated. The difficulty of the task depended to some extent on the adjustment of the device and there was no certainty that the adjustment could be kept constant. The device finally adopted consisted of a handle fitted with a length of three-sixteenth inch diameter steel rod, the last inch of which was bent over at a right angle. This was passed through a quarter