An inspection is a formal meeting, more formalized than a walk-through and typically consists of 3-10 people including a moderator, reader (the author of whatever is being reviewed) and a recorder (to make notes in the document). The subject of the inspection is typically a document, such as a requirements document or a test plan. The purpose of an inspection is to find problems and see what is missing, not to fix anything. The result of the meeting should be documented in a written report. Attendees should prepare for this type of meeting by reading through the document, before the meeting starts; most problems are found during this preparation. Preparation for inspections is difficult, but is one of the most cost-effective methods of ensuring quality, since bug prevention is more cost effective than bug detection.