Some studies expose an experimental group to a treatment and measure its effects. Such an experimental design is the weakest of all designs, and it does not measure the true cause and effect relationship. This is because there is no comparison between groups nor any recording of the status of the dependent variable as it was prior to the experimental treatment and how it changed after the treatment. In the absence of such control, the study is of no scientific value in determining cause and effect relationships. Hence, such a design is referred to as a quasi-experimental design. The following two designs are quasi-experimental.

Pretest and Posttest Experimental Group Design

An experimental group (without a control group) may be given a pretest, exposed to a treatment, and then given a posttest to measure the effects of the treatment.

Posttests Only with Experimental and Control Groups

Some experimental designs are set up with an experimental and a control group, the former alone being exposed to a treatment and not the latter. The effects of the treatment are studied by assessing the difference in the outcomes – that is, the posttest scores of the experimental and control groups.

True Experimental Designs

Experimental designs, which include both the treatment and control groups and record information both before and after the experimental group is exposed to the treatment, are known as post facto experimental designs.

Simulation

An alternative to lab and field experimentation currently being used in business research is simulation. Simulation uses a model-building technique to determine the effects of changes, and computer-based simulations are becoming popular in business research. A simulation can be thought of as an experiment conducted in a specially created setting that resembles the natural environment in which activities are usually carried on. In that sense, the simulation lies somewhere between a lab and a field experiment, insofar as the environment is artificially created but not far different from “reality.” Participants are exposed to real-world experiences over a period of time, lasting anywhere from several hours to several weeks, and they can be randomly assigned to different treatment groups. If managerial behavior as a function of a specific treatment is to be studied, subjects will be asked to operate in an environment very much like an office, with desks, chairs, cabinets, telephones, and such. Members will be randomly assigned the roles of managers, directors, clerks, and so on, and specific stimuli will be presented to them. Thus, the researcher would retain control over the assignment and manipulation, but the subjects would be free to operate as in a real office. In essence, some factors will be build into or incorporated in the simulated system and others left free to vary (participants’ behaviors, within the rules of the game). Data on the dependent variable can be obtained through observation, videotaping, audio recording, interviews, or questionnaires.

Causal relationships can be tested because both manipulation and control are possible in simulations. Two types of simulations can be done: one in which the nature and timing of simulated events are totally determined by the researcher (called experimental simulation), and the other (called free simulation) where the course of activities is at least partly governed by the participants’ reactions to the various stimuli as they interact among themselves.