Final answer:
Administering the tuberculosis vaccination to one group and giving a placebo to another is considered an experimental design. It includes a control group and ensures that any observed effects are due to the treatment itself, as seen in Salk's polio vaccine trial.
Step-by-step explanation:
An experimental design refers to the plan that a researcher follows to ensure that their study adequately tests the hypothesis. Among the given options, administering the tuberculosis vaccination to one group and giving a placebo to another is considered an experimental design. This setup involves key components such as a control group receiving the placebo and the experimental group receiving the actual treatment, which are essential in isolating the effect of the treatment.
Jonas Salk's polio vaccine trial exemplifies a well-designed experiment. This double-blind trial used a large, random sample and included both experimental and control groups, where the latter received a saline solution as a placebo. This rigorous method ensured the validity of the outcomes and minimized the influence of potential biases.