A test subject is typically a paid volunteer who participates in human subject research performed by researchers in various scientific, marketing, and medical fields. A test subject may voluntarily take part in various kinds of market research, clinical trials, or a medical test. For example, before a medication hits the market, researchers perform multiple studies on humans to get the information necessary to ensure it is safe for the general public. As a test subject, the exact duties and responsibilities you take on depend on the research that you participate in and what it involves. In some cases, you simply speak with researchers, provide information or answer questions, and go home. However, some human subject research, such as for certain medical products, may require you to remain at a facility during the trial.