presented keep changing in response to the reactions of the individual (the pilot, the driver, or the emergency handler) to the previous stimulus presented, and not in any predetermined order. Entire business operations, from office layout to profitability, can be simulated using different prospective scenarios. With increasing access to sophisticated technology, and the advancement of mathe- matical models, simulation is becoming an important managerial decision-mak- ing tool. It is quite likely that we will see simulation being used as a managerial tool to enhance motivation, leadership, and the like, in the future. Simulation can also be applied as a problem-solving managerial tool in other behavioral and administrative areas. Programmed, computer-based simulation models in behavioral areas could serve managerial decision making very well indeed.
ETHICAL ISSUES IN EXPERIMENTAL DESIGN RESEARCH
It is appropriate at this juncture to briefly discuss a few of the many ethical issues involved in doing research, some of which are particularly relevant to conduct- ing lab experiments. The following practices are considered unethical:
• Putting pressure on individuals to participate in experiments through coercion, or applying social pressure.
• Giving menial tasks and asking demeaning questions that diminish their self- respect.
• Deceiving subjects by deliberately misleading them as to the true purpose of the research.
• Exposing participants to physical or mental stress.
• Not allowing subjects to withdraw from the research when they want to.
• Using the research results to disadvantage the participants, or for purposes not to their liking.
• Not explaining the procedures to be followed in the experiment.
• Exposing respondents to hazardous and unsafe environments as we saw ear- lier in the case of Johns Hopkins University.
• Not debriefing participants fully and accurately after the experiment is over.
• Not preserving the privacy and confidentiality of the information given by the participants.
• Withholding benefits from control groups.
The last item is somewhat controversial as to whether or not it should be an ethical dilemma, especially in organizational research. If three different incentives are offered for three experimental groups and none is offered to the control group, it is a fact that the control group has participated in the experiment with absolutely no benefit. Similarly, if four different experimental groups receive four different levels of training but the control group does not, the other four groups
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have gained expertise that the control group has been denied. But should this be deemed to become an ethical dilemma preventing experimental designs with control groups in organizational research? Perhaps not, for at least three reasons.
One is that several others in the system who did not participate in the experi- ment did not benefit either. Second, even in the experimental groups, some would have benefited more than the others (depending on the extent to which the causal factor is manipulated). Finally, if a cause-and-effect relationship is found, the system would in all probability implement the newfound knowledge sooner or later and everyone would ultimately stand to gain. The assumption that the control group did not benefit from participating in the experiment may not be a sufficient reason not to use lab or field experiments.
Many universities have a ―human subjects committee‖ to protect the right of individuals participating in any type of research activity involving people. The basic function of these committees is to discharge the moral and ethical respon- sibilities of the university system by studying the procedures outlined in the research proposals and giving their stamp of approval to the study. The human subjects committee might require the investigators to modify their procedures or inform the subjects fully, if occasion demanded it.
MANAGERIAL IMPLICATIONS
Before using experimental designs in research studies, it is essential to consider whether they are necessary at all, and if so, at what level of sophistication. This is because experimental designs call for special efforts and varying degrees of interference with the natural flow of activities. Some questions that need to be addressed in making these decisions, are the following:
1. Is it really necessary to identify causal relationships, or would it suffice if the cor- relates that account for the variance in the dependent variable were known?
2. If it is important to trace the causal relationships, which of the two, internal validity or external validity, is needed more, or are both needed? If only inter- nal validity is important, a carefully designed lab experiment would be the answer; if generalizability is the more important criterion, then a field exper- iment would be called for; if both are equally important, then a lab study should be first undertaken, followed by a field experiment, if the results of the former warrant the latter.
3. Is cost an important factor in the study? If so, would a less rather than more sophisticated experimental design do?
These decision points are illustrated in the chart in Figure 7.7.
Though managers may not often be interested in cause-and-effect relation- ships, a good knowledge of experimental designs could foster some pilot stud- ies to be undertaken to examine if factors such as bonus systems, piece rates, rest pauses, and so on lead to positive outcomes such as better motivation,
MANAGERIAL IMPLICATIONS 167
Figure 7.7
Decision points for embarking on an experimental design.
Is tracing causal effects necessary?
Yes;
and if
Internal validity is more important than
external validity.
No
Generalizability is more important than
internal validity.
Do not undertake an experimental design study.
Both internal validity and external validity
are important.
Engage in a lab experiment.
Engage in a field experiment.
First do a Lab experiment, then, a FIELD experiment.
Are there cost constraints?
Yes No
Engage in a simpler experimental design.
Engage in a more sophisticated design.
improved job performance, and other favorable working conditions at the work- place. Marketing managers would be able to use experimental designs to study the effects on sales of advertisements, sales promotions, pricing, and the like.
Awareness of the usefulness of simulation as a research tool can also result in creative research endeavors in the management area, as it currently does in the manufacturing side of businesses.
SUMMARY
This chapter covered experimental designs, with particular reference to lab and field experiments. We examined how the contaminating variables in detecting the cause-and- effect relationship can be controlled through the processes of matching and randomiza- tion. Issues of internal and external validity and the seven factors that could affect internal validity were discussed. Also, some types of experimental designs that can be used to test cause-and-effect relationships and their usefulness in the context of validity and practi- cality were examined. We also described the ethical issues involved in conducting exper- imental research and the implications for managers in using experimental designs.
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The next chapter discusses how the variables—whether in a field survey or in an exper- imental design—can be measured.
DISCUSSION QUESTIONS AND POINTS TO PONDER
1. What are the differences between causal and correlational studies?
2. In what ways do lab experiments differ from field experiments?
3. Define the terms control and manipulation. Describe a possible lab experiment where you would need to control a variable. Include also a possible variable over which you would have no control but which could affect your experiment.
4. Explain the possible ways in which you can control ―nuisance‖ variables.
5. What is internal validity and what are the threats it stands exposed to?
6. Explain the concept of ―trade-off between internal validity and external validity.‖
7. Explain fully how you would demonstrate to machine operators and convince them through research that thorough knowledge of the operating policies and procedures (by reading the manual) would eliminate almost all ―on-the-job‖ accidents.
8. ―If a control group is a part of an experimental design, one need not worry about controlling other exogenous variables.‖ Discuss this statement.
9. A researcher wants to set up a lab experiment to test the effects of different kinds of leadership styles on followers‘ attitudes. The three particular kinds of leadership styles she is interested in are autocratic, democratic, and participative. You are asked to enlist some students to play the part of followers. What cover story would you give the participants?
10. Comment on the following statement: ―Because the external validity of lab experi- ments is not usually high, they are useless for investigating cause and effect relation- ships in organizations.‖
11. ―Covariance—that is, two variables varying together either positively or negatively—
and control are integral aspects of experimental designs.‖ Discuss.
12. ―The Solomon four-group design is the answer to all our research questions pertain- ing to cause-and-effect relations because it guards against all the threats to internal validity.‖ Comment.
13. Below is an adapted note from Business Week published some time ago. After read- ing it, apply what you have learned in this chapter, and design a study after sketch- ing the theoretical framework.
The Vital Role of Self-Esteem
Why do some people earn more than others? Economists focused on the impor- tance of education, basic skills, and work experience—what they called human capital—on increased productivity, and said these were reflected in greater earning power. Researchers also found that self-esteem was instrumental in acquiring human capital.
DISCUSSION QUESTIONS 169
14. Design a study to examine the following situation.
An organization would like to introduce one of two types of new manufacturing processes to increase the productivity of workers, and both involve heavy invest- ment in expensive technology. The company wants to test the efficacy of each process in one of its small plants.
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