Final answer:
Observational studies involve data collection without intervention, while experimental studies require manipulation of variables to test a hypothesis. Both are crucial in scientific research as they provide varied insights.
Step-by-step explanation:
The main difference between observational and experimental data lies in the interaction with the subject. In an observational study, researchers collect data without intervening or manipulating any variables. They simply observe and record what occurs naturally. This type of study is helpful when experimental studies are either unethical, impractical, or impossible to perform. Examples include political polling or case studies, where researchers gather information to find patterns.
Conversely, an experimental study involves deliberate manipulation of variables to test a hypothesis. Here, researchers create a controlled environment to isolate the effects of a treatment or an intervention. A classic example is a clinical trial, such as Jonas Salk's polio vaccine experiment, where participants are given either a treatment or a placebo to measure the treatment's effectiveness.
Both observational and experimental studies are integral to scientific research as they provide different kinds of data. Observational studies offer a broad view of naturally occurring phenomena, whereas experiments provide causative links between variables.