ABSTRACT
This chapter introduces the general concept of an experiment and goes on to outline basic uses of this design in psychological research. Design in which an independent variable is manipulated, all other variables controlled and a dependent variable is measured for changes caused by the independent variable. There are always alternative interpretations of findings. The trouble here is that as heat goes up, so do certain other factors. For instance, the warmer it is, the more people there are out in public places, the longer are the queues for ice cream, the longer are the traffic jams and so on. It may not be heat that is the direct cause of increased aggression, but one of these other related factors. The trouble is that with this kind of non-experimental design the author's can’t exclude these other factors, as they operate in everyday life.
