Standardized educational test (also known as standardized achievement test) is different from classroom tests made by teachers, and its compilation is based on a detailed content outline. It uses standardized test procedures and grading standards, and provides norm data to explain scores. It has many types. Some are survey tests, which aim to put forward overall indicators to illustrate students' mastery of subject content. Some survey tests (subject tests) only contain one subject content; Other subject exams are complete sets, including six, seven or even more subjects.