Advantages and Limitations:
Experimental approach represents the most powerful method for testing hypothesis of the cause and effect relationship between variable. Because of its special controlling properties on experiment it offers greater control than any
other research approach that the independent variable (e.g. diet, drug, dosage, teaching approach) has an effect on the dependent variable (e.g. weight loss, recovery of health, learning, etc.). The great strength of experiments then lies inthe confidence with which casual relationship can be inferred.
This approach has several limitations. Many interesting variables are not amendable to experimental manipulation. A large number of human characteristics e.g. health history, age, gender, can not be randomly conferred on people.
Another problem in experiment is Hawthorne effect or placebo effect. It is the effect on the dependent variables caused by subject's awareness, that they are special participants under study e.g. the knowledge of being included in the study may be sufficient to cause people to change their behaviour. For examplewhen a staff nurse knows that slhe has involvement in research to find the quality care being offered, itself will improve the quality of care.