Standardized tests should be reliable and valid. Reliability refers to the test construction. Reliable tests should be dependable to report similar results when taken by similar groups over a period of time. In other words, the test is free from errors in its construction and measurement. Therefore, if a test is reliable, it should be meaningful.
Validity refers to the test taking.
The test is actually measuring what students are learning. Test publishing companies are very concerned about reliability and validity. They carefully monitor the reliability of standardized tests. Validity is a factor that is more difficult to control. These scores can be utilized to evaluate a school district, a school, a particular education program, a teacher, and a student.