In computational linguistics, which began in the 1950's with machine translation, systems that are based mainly on the lexicon have a longer t r a d i t i o n than anything e l s e - - - f o r these purposes, twenty f i v e years must be allowed to count as a tradition. The bulk of many of the early translation systems was made up by a d i c t i o n a r y whose e n t r i e s consisted o f a r b i t.