The Jargon File (version 4.4.7, 29 Dec 2003):

ad-hockery
 /ad?hok'@r?ee/, n.

    [Purdue]

    1. Gratuitous assumptions made inside certain programs, esp. expert
    systems, which lead to the appearance of semi-intelligent behavior but are
    in fact entirely arbitrary. For example, fuzzy-matching of input tokens
    that might be typing errors against a symbol table can make it look as
    though a program knows how to spell.

    2. Special-case code to cope with some awkward input that would otherwise
    cause a program to choke, presuming normal inputs are dealt with in some
    cleaner and more regular way.

    Also called ad-hackery, ad-hocity (/ad-hos'@-tee/), ad-crockery. See also 
    ELIZA effect.

    [73-10-31]

    This is ad-hockery in action.


The Free On-line Dictionary of Computing (30 December 2018):

ad-hockery

    /ad-hok'*r-ee/ (Purdue) 1. Gratuitous assumptions
   made inside certain programs, especially expert systems,
   which lead to the appearance of semi-intelligent behaviour but
   are in fact entirely arbitrary.  For example, fuzzy-matching
   of input tokens that might be typing errors against a symbol
   table can make it look as though a program knows how to spell.

   2. Special-case code to cope with some awkward input that
   would otherwise cause a program to fail, presuming normal
   inputs are dealt with in some cleaner and more regular way.
   Also called "ad-hackery", "ad-hocity" (/ad-hos'*-tee/),
   "ad-crockery".

   See also ELIZA effect.

   [Jargon File]

   (1995-01-05)