Final answer:
Case-control studies are less expensive and require fewer resources than structural experimental studies because they are observational, retrospective, and often make use of existing data. In contrast, structural experimental studies demand extensive resources to conduct controlled interventions and monitoring, resulting in higher costs.
Step-by-step explanation:
The difference in case-control studies compared to structural experimental studies regarding cost and facilities primarily revolves around the nature of these research methods. Case-control studies, which are a type of observational study, tend to be less expensive than experimental studies as they are retrospective and often utilize existing records or patient interviews to gather data. As such, they do not require the infrastructure or resources necessary for conducting controlled experiments and typically do not involve interventions. On the other hand, structural experimental studies are designed to test hypotheses under controlled conditions, requiring more resources. This includes facilities for conducting the intervention, monitoring the subjects, and systematically collecting data. Experimental studies may involve large sample sizes and require substantial funding to manage all phases of the research, including the application and isolation of treatments as well as ensuring adequate control conditions. These factors contribute to the higher cost and facility demands of experimental research. To illustrate this, let's consider the polio vaccine trial conducted by Jonas Salk in 1954. This experimental study required administering the vaccine or placebo to thousands of children and then monitoring the incidence of polio. Such a study would necessitate significant medical resources, personnel, and oversight, hence, incurring higher costs compared to a case-control study on the same topic.