Imagine you are asked to compare two different but similar types of apples. Would it be easier to evaluate them by trying each apple separately or by trying them side-by-side? Most people would prefer them side-by-side. In fact, we all tend to perform better when comparing than in more general evaluations, an idea going back at least to 1927 and Thurstone's Law of Comparative Judgment.
ComPAIR presents peer answers in pairs for students to evaluate and give feedback on. By placing answers in a paired context, students can use their inherent ability to compare in evaluating the answers. They can also use both answers as references when writing feedback. This approach helps students identify strengths or weaknesses that may not be as evident for a single isolated answer, encouraging richer peer feedback and deeper critical thinking.