What are the sources of treatment misidentification?

Question

What will be an ideal response?

Answer 1

Treatment misidentification occurs when subjects experience a treatment that wasn’t intended by the researcher. Treatment misidentification has at least three sources:
1. Expectancies of experimental staff. Change among experimental subjects may be due to the positive expectancies of the experimental staff who are delivering the treatment rather than due to the treatment itself. Such positive staff expectations can create a self-fulfilling prophecy and can occur even in randomized experiments when well-trained staff convey their enthusiasm for an experimental program to the subjects in subtle ways. These expectancy effects can be very difficult to control in field experiments. However, in some experiments concerning the effects of treatments such as medical drugs, double-blind procedures can be used. Staff will deliver the treatments without knowing which subjects are getting the treatment and which are receiving a placebo—something that looks similar to the treatment but has no effect. In fact, the prison experiment discussed earlier in this chapter used a double-blind procedure to randomly assign inmates to a security classification category. In the experiment, only the executive director of the corrections department and the director of classification were aware of the research. Correctional staff, other individuals who worked with the inmates, and the inmates themselves were unaware of the study. In this way, any expectancies that the staff may have had were unlikely to affect inmate behavior.
2. Placebo effect. Treatment misidentification may occur when subjects receive a treatment that they consider likely to be beneficial and then improve because of that expectation rather than the treatment itself. In medical research, the placebo is often a chemically inert substance that looks similar to the experimental drug but actually has no medical effect. Research indicates that the placebo effect produces positive health effects in two thirds of patients suffering from relatively mild medical problems (Goleman, 1993). Placebo effects can also occur in social science research. The only way to reduce this threat to internal validity is to treat the comparison group with something similar.
3. Hawthorne effect. Members of the treatment group may change in terms of the dependent variable because their participation in the study makes them feel special. This problem can occur when treatment group members compare their situation to that of the control group members who are not receiving the treatment. In this case, this is a type of contamination effect. However, experimental group members could feel special simply because they are in the experiment. The Hawthorne effect is named after a famous productivity experiment at the Hawthorne electric plant outside Chicago. Workers were moved to a special room for a study of the effects of lighting intensity and other work conditions on their productivity. After this move, the workers began to increase their output no matter what change was made in their working conditions, even when the conditions became worse. The researchers concluded that the workers felt they should work harder because they were part of a special experiment.