"Next, a few words that will have to be used repeatedly. Consider the simple example in which, under the influence of sunshine, pale skin changes to dark skin. Something, the pale skin, is acted on by a factor, the sunshine, and is changed to dark skin. That which is acted on, the pale skin, will be called the OPERAND, the [causing] factor will be called the OPERATOR, and what the operand is changed to will be called the TRANSFORM. 5