5. It has been argued that the search for “a single, all-purpose, neutral analytical concept which marks out federal question jurisdiction” is futile. See Cohen, The Broken Compass: The Requirement that a Case Arise “Directly” Under Federal Law, 115 U. Pa. L. Rev. 890 (1967).

Instead, Professor Cohen put forward a “pragmatic” test that includes consideration of caseload volume, significance of the federal or state law, comparative judicial expertise, and the need to protect federal interests. For a criticism, see Ryan, It’s Just Not Worth Searching for Welcome Mats with a Kaleidoscope and a Broken Compass, 75 Tenn. L. Rev. 659 (2008), urging a return to the Holmes test.