Most Of Your "Nudges" Are Just Interruptions In Costume

In 2008, Richard Thaler and Cass Sunstein needed an example simple enough to explain the whole of economic theory from a single application. They used a cafeteria menu. By moving the fruit to eye level and sending the fries to the periphery, they demonstrated that a slightly adjusted environment could convince thousands of students to make healthier choices. No one is stopped from choosing fries and the fries-loving student still chooses fries. But the undecided student chooses the apple, simply because it is now right in front of him. In 2017, Thaler was awarded the Nobel Prize in Economics for his body of work, including the development of “The Nudge Theory” with Sunstein. In the years that followed, product teams building mobile applications have taken to referring to any call-to-action on-screen as a nudge. The design of an effective nudge There are two requirements for a nudge to work reliably. The user should have an apparent desire for the thing they are being nudged toward, and the nudge should appear at the moment when this desire is at its peak. The first requirement ensures the user has a mental model of the target action, meaning they understand roughly what they are supposed to do. The second requirement serves to remove any extraneous context, ensuring the nudge does not fail due to poor timing. A checkout confirmation modal shown straight after launching the application will fail miserably as a nudge. The desire to checkout is non-existent at the launch moment, and the context of the action has little to do with the action itself. A tooltip shown after a specific number of unsuccessful attempts to checkout after viewing the cart, however, is a nudge. It has the desired behavior and the right timing. Why the difference shows up in the numbers In the example with Duolingo, the product team has effectively used the framing of an existing streak as a reference point for the next level of engagement. The players who saw streak-based progress notifications