Describe What Is Involved in the Experimental Method as It Is Used in Psychology and Its Limitations

In psychology, the experimental method involves the manipulation of some aspect of a situation, and observing the effects this has on a particular behavior. In technical terms, the former is the independent variable (IV), and the latter the dependant variable (DV). Only the investigations which involve the manipulation of the independent variables is part of the experimental method. Basically, in other words, we can say that experimental method is the type of research which involves the investigation of the relationship between two (or more) factors by deliberately intervening one factor in a situation and observing the effects of that modification on other aspects of the situation. Examples of variables that can be used, manipulated and controlled in experimental method are: Behaviors, events or other characteristics that can change or vary in some way. By employing both experimental and control groups in an experiment, investigators are enabled to rule out the possibility that something other than the experimental manipulation produced the results observed during the experiment. This type of research can be broadly divided into three main types: The Laboratory Experiment, The Field Experiment and The Natural Experiment.

In a laboratory experiment, there is a systematic variation of the independent variables while other irrelevant variables are kept constant. The basis of a laboratory experiment is the use of control. The researcher attempts to eliminate or control other variable that might intervene with the purity or accuracy of the experimental relationship between the IV and the DV. Due to the control of extraneous variation in a laboratory experiment, it becomes very helpful for the experimenter to draw conclusions about the influence of IV. By carrying out the investigation in the laboratory, it enables the experimenter to measure behavior with a greater accuracy and precision than would be possible in the natural environment. This method of research is used to make replication of theories and investigations easier.

Although laboratory experiments are pretty useful, they have numerous limitations which do not make it a very appropriate and accurate research method. One of the limitations of laboratory experiment is that participants' behavior might be artificial and not valid to real life situations as it is being studied in a contrived situation. Participants/subject may tend to adopt roles or adjust their behavior because they do not passively respond to psychological stimuli but react to the situation in number of active ways; this limits the accuracy of the results as the participants' behavior is adopted and adjusted/manipulated.

Laboratory experiments depend on the extensive use of volunteers, and research proves that volunteers react differently to non-volunteers, so it might lead to an unusual type of participants being used which can lead to inaccurate results, thus limiting the success of this research method. Also, experiments which use animals experience various problems of interpretation and relevance. A very vital part of psychological investigation that could be a limitation for laboratory experiments is ethical problem because laboratory experiments tend to be potentially burdened and weighted down.

Another vital part of the experimental method includes field experiment. Field experiment is where the research is performed in the natural environment rather than in the controlled circumstances of a laboratory. Field experiments generally randomize subjects or sampling units into treatment and control groups and compare outcomes between these groups. In this method of research there could be some degree of control but obviously less than the degree of control possible in the laboratory. The researcher modifies/manipulates the IV and then observes its effects on the behavior or attitude in the more natural setting. This research method has an advantage of economy as the experimenter can create conditions of interest and observe the results rather than waiting for them to occur naturally. Field experiments are used to have a higher degree of ecological validity as the investigation takes place within a natural setting, thus results are likely to be relevant and based on real life behavior.

Just like any other research method, field