Testing serves several purposes including informing learners and teachers of strengths and weaknesses, motivating learners, and determining if learning objectives have been achieved. Tests can be classified based on their purpose such as screening, placement, or achievement. They can also be classified based on their characteristics such as being direct or indirect, criterion-referenced or norm-referenced. Proper test design considers guidelines around moderating tasks, ensuring an appropriate level of difficulty, avoiding bias, and standardizing examiners.