Although an ideal sitter is one who is both personally experienced with the substance being used, as well as one trained to deal with any potential psychological or medical crisis that may arise, arguably the most important qualities may be the willingness to help, the responsibility needed to stay sober enough to be fully present, and the ability to be relaxed, accepting, and not interfere with the experience beyond the wishes of the user. A sitter should be willing to research the substance in question, and understand when to call for professional medical assistance.