The security supervisor operates a component of the security services branch consisting of a museum, gallery, support element, or a part thereof; provides safety and information for the visiting public and employees, protection for the collections, security for the corporation assets, and safety information and a controlled environment for the public; and performs other related responsibilities. Roles cover administrative responsibilities, human relations responsibilities, and training and development responsibilities. The basic knowledge required is that of the principles of protecting material, buildings, information, and people against harm, loss, or damage; the position demands a special knowledge of the security policies, regulations, and procedures applicable to the museum. The complicated mix of communications, alarm systems, museum personnel, the public, and the high value of the collections requires the highest level of attention and precise mental and sensory coordination. The functions of the security guard can be summarized as prevention, protection, enforcement, detection, investigation, emergency services, reporting, inspections, and general services. The work requires the completion of an 80-hour training course that covers first aid, fire and emergency procedures, protection of evidence, security techniques and systems, human relations, and criminal law. Because the security guard must work under limited supervision and make on-the-spot decisions, the officer must develop the ability to be explicit and correct in the various situations encountered.