Optical answer sheet
（重定向自Scantrons）
An optical answer sheet or "bubble sheet" is a special type of form used in multiple choice question examinations. Optical mark recognition is used to detect answers. The most well known company in the United States involved with optical answer sheets is the Scantron Corporation, although certain uses require their own customized system. The terms "Optical answer sheet" and "scantron" have become more or less interchangeable.