  Current dark pattern research tells designers what not to do, but how do they
know what to do? In contrast to prior approaches that focus on patterns to
avoid and their underlying principles, we present a framework grounded in
positive expected behavior against which deviations can be judged. To
articulate this expected behavior, we use concepts -- abstract units of
functionality that compose applications. We define a design as dark when its
concepts violate users' expectations, and benefit the application provider at
the user's expense. Though user expectations can differ, users tend to develop
common expectations as they encounter the same concepts across multiple
applications, which we can record in a concept catalog as standard concepts. We
evaluate our framework and concept catalog through three studies, illustrating
their ability to describe existing dark patterns, evaluate nuanced designs, and
document common application functionality.
