The dependent variable, “crying,” must also be defined. It must be done in such a way that dependent observers would reliably agree on its occurrence. Do intermittent sounds constitute “crying,” or must the sound be sustained for a given period of time? Is a whimper also a cry or must the sound reach a certain level of intensity (some decibel level)? All these decisions must be made before the experiment is conducted. Otherwise, the results might not mean-anything to anyone except the experimenter.