The Myth of 'Seven, Plus or Minus 2'
This article proposes that the optimal number of menu items cannot be reduced to the generalized 'Magic Seven, Plus or Minus Two' (7±2). The author proposes that instead, when planning a site information architecture, the two most important considerations are breadth versus depth and the display of information.
Kalbach, James. Dr. Dobb's (2002). Articles>Information Design>History>Cognitive Psychology