ABSTRACT
In the previous experiment children were faced with lines already divided into segments and asked to compare them; in this experiment they are asked to locate a segment on a straight line equal to a segment given on another straight line. In order to do this various lengths of string are stretched in various positions between nails on a board, each string having a bead threaded on it. One of the beads is moved along one string and the subject is asked to make another bead travel the same length journey on its string. A blank wooden ruler, a stick, strips of plain paper, threads of various lengths and a pencil are available. During stage 1 and substage 2a the children are able to solve the problem if starting points and strings are in alignment, but as soon as this is not so they fail—if the strings are staggered they simply put their bead opposite the experimenter’s and disregard the inequality of the journeys made. At substage 2b this problem is solved intuitively (by looking), but there is failure when the strings are of different lengths or not parallel nor in alignment, or when a child is asked to run its bead from the opposite end of the string. They attempt to measure but fail to see the need for accurate subdivision and for taking into account the point of departure as well as that of arrival. Moreover in all this the function of measurement is still only a secondary one. It is only used to verify a judgment reached on an intuitive basis, whether by visual estimate, or by using hands, etc.
