“Formality Considered Harmful: Experiences, Emerging Themes, and Directions on the Use of Formal Representations in Interactive Systems” by Shipman and Marshall (1999)

In this paper, we describe how creators of systems that support intellectual work like design, writing, or organizing and interpreting information are particularly at risk of expecting too great a level of formality from their users. To understand the effects of imposing or requiring formality, we draw on our own experiences designing and using such systems.

http://www.csdl.tamu.edu/~shipman/formality-paper/harmful.html

One of my long-time favorites!