If you wish to scale sensation on a population that does not know a whole lot about numbers, you may be in a lot of trouble if you use the magnitude estimation procedure described thus far. This problem is inherently obvious if you think about a small child who may not necessarily know that the number 40 is twice as much as the number 20. However, there is no need to worry, there is a second magnitude estimation tool at your disposal…cross modality matching. In cross modality matching, a subject is asked to physically adjust the intensity of one stimulus to match the intensity of another stimulus. An example of cross-modality matching is asking a subject to adjust the brightness of a light to match the loudness of a presented tone (Snodgrass et al, 1985).