Board of Certified Safety Professionals (BCSP) Practice Exam

Which precaution is essential for sound experimental design?

1. Random sampling

2. Including a control group

3. Limitations on variables

4. Predictive modeling

The correct answer is: Including a control group

Including a control group is essential for sound experimental design as it allows researchers to isolate the effects of the independent variable. A control group serves as a baseline, providing a point of comparison against which the experimental group can be evaluated. This helps in determining whether any observed changes in the experimental group are indeed due to the experimental treatment rather than other confounding factors. The presence of a control group helps to enhance the validity of the experiment by minimizing the impact of variables that are outside the experiment's focus. By controlling certain conditions and having a group that does not receive the treatment or intervention, researchers can more accurately attribute any differences in the outcomes to the experimental conditions being tested. Random sampling, while also a critical aspect of experimental design, primarily relates to how participants or subjects are chosen to participate in the study, which helps ensure that the sample is representative of the larger population. Limitations on variables are important as they help manage extraneous factors within the experiment, but they do not specifically provide a means of comparison as a control group does. Predictive modeling, on the other hand, is more about anticipating future outcomes based on current data and does not directly influence the comparative nature of experimental design.