1. A word recognition system for recognizing an input signal entered via a shorthand-on-keyboard interface, the system comprising: a core lexicon comprising commonly used words; an extended lexicon comprising words not contained in the core lexicon; a recognition module for recognizing words associated with the input signal; a selector module for outputting an output word associated with the input signal from the core lexicon; and a module for admitting a candidate word associated with the input signal to the core lexicon, upon selection of the candidate word by the user.