Ability, or aptitude, is a students potential for learning. Measuring a students ability is different than measuring achievement. Achievement has to do what the student has learned. This is seen in end of the unit tests, quizzes, practice work, and portfolios. Ability, on the other hand, has more to do with how the student learns. Ability data can give teachers an "insight into students' readiness to demonstrate problem-solving skills and learn in different situations and learning environments." (https://blog.riversideinsights.com/ability-data-student-potential-cogat?_ga=2.239437057.324835302.1668783650-847823927.1668783650)

Ability is not only influenced by experiences related to formal schooling but is influenced by all experiences, in and out of the classroom. When we measure it, we look at problem solving and reasoning processes. "The Cognitive Abilities Test™ (CogAT®) offers content to measure general and abstract inductive and deductive problem solving across three areas – Verbal, Quantitative, and Nonverbal (figural) reasoning." (same) The composite scores give us an over-all idea of a students general reasoning abilities.