Defintion:
Standards-based assessment: A test or other type of assessment for which the criteria and information is taken directly from content that a student has been taught or is expected to learn. This is in opposition to more typical achievement or aptitude tests, which examine more generalized knowledge.
Standards-based assessments are particularly helpful when a school district or state education department has defined a set of learning standards that each student needs to learn. The test can then measure not only student achievement, but teacher effectiveness as well.