Issues in Psychological Measurement #1

What is measurement? Some would argue that measurement is nothing more than the process of assigning numerical values to various objects or attributes. Although this might seem like a reasonable approach to take at first glance, it cannot be correct if measurement is to have any meaning whatsoever.

Consider the following situation: there are five pieces of wood. The lengths of these pieces of wood are 5 cm, 5 cm, 6 cm, 7 cm, and 7 cm. The average length of these pieces of wood is 6 cm.

Now co...