1 Anyone who doubts the astonishing, if sometimes misguided, ingenuity of designers of IR mechanisms is referred to the brief description by Roberts [116] (writing in 1984 on the history of the thesaurus in IR) of a system operating at RRE Malvern in 1955. This might be described as a peek-a-boo system, except that the "cards" were 12"x12" metal plates, swinging on a heavy metal post, and "punched" by means of a Black & Decker drill!

2 A very much later review of machine translation (Hutchins [98]) prompts the thought that, whatever doubts one may have about computer-based IR, compared to MT it has been outstandingly successful.

3 Seventeen years later, Sparck Jones and Tait [113] experimented with a very similar procedure, without referencing Hutchins.