Although simulation and field studies can be used to increase the realism of experiments, there are risks as well as advantages to these techniques. The ob- vious advantage of both procedures is that they allow researchers to investigate behavior in more life like situations and, therefore, should increase the chances that the experimental results accurately reflect natural events. The disadvantage of both procedures is that allowing nature to intrude on an experiment means that the researcher often loses some control over the situation and risks compromising the internal validity of the experiment.