An experiment involves manipulating one variable – which we call the Independent Variable and then seeing whether this affects a second variable, which we refer to as the Dependent Variable. To explain this, we describe an experiment conducted by Scheier and Carver (1977) in which the independent variable ‘self-awareness’ was manipulated by having participants either watch themselves in a mirror or not. These two levels of self-awareness high self-awareness (mirror present) and low self-awareness (mirror not present ) formed the two experimental conditions. The prediction was that people in high self-awareness would show more extreme emotional responses. Participant’s self-reported emotions were measured. These emotions provided the dependent variable in the experiment.
The experimental method could further be divided into two sub-categories (i) Laboratory method (ii) Field method.
The majority of experiments are conducted in a laboratory. In some studies, the laboratory is equipped with television, video cameras, computer monitors, microphones and other experimental apparatuses. In other cases, the laboratory is a simple room with a table and chair wherein a participant fills out a questionnaire.
The benefit of conducting a laboratory experiment is that conditions could be highly controlled. Putting it in another way, within the confines of the laboratory, everything ( example: environment, temperament, instructions given by the researcher ) apart from the independent variable can be held constant. This way if changes in the independent variable are including changes in the dependent variable, we can very confidently say that the changes in the dependent variable are caused by the independent variable.
Another benefit of experiments conducted in such a controlled environment is that they can be replicated, which would otherwise be more difficult to create outside the laboratory. Laboratory experiments have been used to study a wide range of social phenomena and have formed the basis for a number of highly influenced theories.
The Advantages and Disadvantages of Laboratory method are:
- Although the high degree of control over conditions allows us to infer causality from the finding – it also makes the experiment rather artificial i.e. the experiments lack external validity.
- Information that participants pickup from the experimental context leads them to guess what the experimenter is predicting will happen. When this happens it will influence the ‘behavior’ which the experimenter is looking for because the internal mental processes of the participant cannot be controlled.
- Experimenters themselves may also pose a risk to the validity of an experiment. ‘Experimenter effects; are subtle cues or signals that are given out by experimenter who knows the experimental hypothesis – ex: body language, eye movements, tone of voice.
Experiments are not only confined to the laboratory. They are also conducted in naturalistic settings. For example given a situation; wherein an individual requires help, how many people come forward to help and why? Field experiments have greater external validity ( not being artificial but genuine ) than a laboratory experiment. They are less likely to be influenced by ‘demand characteristics’ participants typically have no idea that they are taking part in a study.