To be considered complete, a report must answer the 5 W's (who, what, where, when, why) and the H (how). The 5 W's refer to who was involved, what happened, where it took place, when it took place, and why it happened. Ten common types of human mistakes are forgetfulness, misunderstanding, wrong identification, lack of experience, willful ignoring of rules, inadvertent sloppiness, slowliness, lack of standardization, surprise, and intentional mistakes.