Learning assessments are convenient, easy to implement at any moment and provide measureable standards. Without tangible testing data, teachers can't figure out what material needs to be retaught and what material has been grasped well by students. Written tests, for example, are the same for all students, are judged objectively and provide longterm data for the whole group rather than a single individual.
Standardized testing can be locally developed, or customized to match the needs of students from a particular location and school program. Locally developed testing is improved upon over long periods of time based on available data from student scores. The school board, teachers and others contributing to the writing of school programs meet to discuss the strengths and weaknesses of the material and the assessments that test the knowledge of that material.
Traditional assessments, such as tests and quizzes, prove more difficult to complete for some than others. Students with more active, visual, conceptual or artistic learning styles have difficulty memorizing and repeating knowledge in the form of multiple choice questions, short essays, "True or False" questions or similar formats. Simply because a student isn't a good test taker doesn't prove that she hasn't mastered the material in a different way. Some learning assessments test only a specific way of retaining information.
Scores, grades and other data from learning assessments is summative rather than formative. Summative data gives a broad overview of the complete picture. The details, however, prove most important when figuring out what changes need to be made to the program, what material needs to be stressed and what material is easily understood. Teachers understand that students pass or fail, but not why they pass or fail. This makes it more difficult to get to the bottom of learning struggles and fix the program to match each student's needs.