Every science has laboratory.The term is usually used to denote a room where psychologist can observe behavior which at the same time maintaining some degree of control over the physical environment which might otherwise effect the behavior of the people being observed.
The main characteristics of laboratory experiment is the investigator's ability to control and alter the variables being tested.Because of this control the investigator is able to eliminate many of the extraneous variables that might otherwise affect the results of of the experiment.For example.......Heat, Noise, Distraction or the nature of the participants themselves.
Merit or Advantages
1. Great control over conditions of the study can be specified more clearly.
2. Participants can be selected.
3. Participants can be placed in conditions more systematically.
4. Because of the experimenter's ability to control the effect of extraneous variables, Cause and effect relationship can be established.
5. The laboratory offers the experimenter the opportunity to measure behavior with a great precision than would be possible in the natural environment.
6. The laboratory also allows the research scientist to simplify the complex events of the natural world by breaking them down into simpler components parts.We can say it as experimental reductionism.
Demerits or Disadvantages
1. It is claimed that the laboratory lacks relevance to the real life, in that tasks explored in the laboratory may not transfer to the outside world.
2. Participants may react to the laboratory setting either by the acting in the way they feel the experiment requires (Demand Characteristics) OR by displaying artificial behavior because of their concern that they are being judged in same way (evaluation apprehension).
3. Avoiding demand characteristics and evaluation apprehension after involves the use of deception in laboratory research raising serious questions concerning the ETHICS of such investigations.
2. "Any region within which certain specified phenomena occure".
A field experiment applies the scientific method to experimentally examine an intervention in the real world (or as many experimentalists like to say, naturally-occurring environments) rather than in the laboratory. Field experiments, like lab experiments, generally randomize subjects (or other sampling units) into treatment and control groups and compare outcomes between these groups.Any experiment carried out in natural settings rather than in the artificial environment of a laboratory.
This type of experiment replace the artificial settings of the laboratory with a more natural one.Participants are not aware that they are taking part in an experiment.
Merits or Advantages
1. By focusing on behavior in natural setting the experimenter increase the external validity of the findings.
2. Because participants are unaware of their participation in an experiment, they are less likely to display demand characteristics or evaluation apprehension.
3. The experimenter maintains control over the independent variable.
Demerits or Disadvantages
1. Because many manipulations of the independent variable may be quite subtle, they may pass by unnoticed by the participants.Similarly the reactions of the participants may also be subtle and may pass by unnoticed by the experimenter.
2. In control to the laboratory setting the experimenter has less control over the effect of extraneous variables which might interfere with the purity of the cause-effect relationship.
3. Because participants are not aware of their participation in an experiment , there are ethical concerns such as invasion of privacy and lack of informed consent.