Testing intelligence focuses on measuring a person’s ability to think, reason, and solve problems, while testing knowledge checks what a person has already learned, such as facts, skills, or subject content. Intelligence tests look at potential and adaptability, whereas knowledge tests focus on mastery of information taught.

Intelligence testing is appropriate when identifying learning abilities or cognitive strengths, while knowledge testing is useful for exams, certifications, or checking progress in school. However, using intelligence tests to measure subject mastery can be unfair, and relying only on knowledge tests cannot show how well a person can adapt to new challenges. Both have their place, but the purpose should guide which is used.