I was surprised to learn the sheer effort that goes into planning where to put things. Had a talk at a neuroscience workshop from a computer scientist at Tesco, who develops new data mining algorithms to figure out which items are most commonly bought together (idea being same techniques cd be used to search for correlations in neuronal activity). I had assumed they just used common sense - the toothpaste near the toothbrushes etc - but no, way more sophisticated than that!

N.