Models for the generation of writing units in handwriting under variation of size, slant, and orientation

Abstract

This study presents empirical data concerning the psychological validity of fourteen different computational models for the production of writing strokes in handwriting. An earlier study reviewed the mathematical properties of several published models and of some further models developed by the authors. In the present study these fourteen models were compared with regard to the criterion that global parameters, such as size, slant, and orientation of the handwriting, should not affect the fit between the simulated writing trace and the specimens of natural handwriting. This prediction was based upon a characteristic of a psychomotor model of handwriting, developed by one of the authors, which assumes that global parameters are set by independent and hierarchically higher processors than the more peripheral, biophysical-force generators that produce the particular concrete stroke trajectories. The results show that those models that produce a close fit to natural handwriting in a standard condition, yield the best fits under variation of size, slant, and orientation. All models with consistent results appear to have in common that the timing of the transition points remains unaffected by global parameter settings.