An implement used to facilitate work, especially precision work. An implement used to facilitate work, especially precision work. A protocol is a plan specification which has sufficient level of detail and quantitative information to communicate it between domain experts, so that different domain experts will reliably be able to independently reproduce the process. A plan specification that allows different domain experts to reliably and independently reproduce a process. In Phase 2 trials, an experimental study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety. Phase 2 Clinical Trial A clinical trial is a research study using human volunteers to answer questions about treatments for diseases and conditions. Clinical trials are conducted in phases. The trials at each phase have a different purpose and help scientists answer different questions. A research study using human volunteers to answer specifc health-related questions. Phase 0 is a recent designation for exploratory, first-in-human trials conducted in accordance with the United States Food and Drug Administration's (FDA) 2006 Guidance on Exploratory Investigational New Drug (IND) Studies. Phase 0 trials are also known as human microdosing studies and are designed to speed up the development of promising drugs or imaging agents by establishing very early on whether the drug or agent behaves in human subjects as was expected from preclinical studies. Phase 0 Clinical Trial In Phase I trials, researchers test an experimental drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects Phase 1 Clinical Trial number of human participants in the study (trial). In Phase 4 trials, post marketing studies delineate additional information including the drug's or treatment's risks, benefits, and optimal use. Phase 4 Clinical Trial Phase 3 Clinical Trial In Phase 3 trials, an experimental study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the experimental drug or treatment to be used safely. Every clinical trial in the United States must be approved and monitored by an Institutional Review Board (IRB). An IRB is an independent committee of physicians, statisticians, community advocates and others whose objective is to ensure that a clinical trial is ethical and the rights of study participants are protected. ClinicalTrials.gov is an ICMJE-acceptable public registry, offering up-to-date information for locating clinical trials for a wide range of diseases and conditions. The U.S. National Institutes of Health (NIH), through its National Library of Medicine (NLM), developed this site in collaboration with the Food and Drug Administration (FDA), as a result of the FDA Modernization Act, which was passed into law in November 1997. NCT00000419 A service that produces a physical object or data, such as a custom micro-array chip, a made to order antibody, or a behavioral dataset A service that produces a physical object or data.