The expression "comparing apples and oranges" is a commonly used idiom. The phrase refers to the comparison of two objects, groups or ideas that are different enough from each other that comparing them seems erroneous.

Example of Usage

An example of a way the idiom can be used in a sentence is, "You cannot compare Stephen King to Nicholas Sparks. That's comparing apples and oranges." Because these novelists write in different genres and have very different writing styles, the idiom indicates King and Sparks cannot be fairly compared.

Criticism of the Idiom

As common as the idiom is, the idea of apples and oranges as dissimilar has been criticized. They are both fruits, they are approximately the same size and shape, both grow on trees, and both have seeds. Law professor Eugene Volokh argues against the apples and oranges idiom in his blog for law professors: "We compare apples and oranges all the time! We compare them by price, by how much we like the taste, by likely sweetness and ripeness, by how well they’ll go in a tasty fruit cocktail, and so on."