The 2/3 power law: when and why?
This paper presents the origin of some reported observations, which links the kinematics of handwriting with a movement trajectory, best known as the 2/3 power law. Using computer simulations, it is shown that the vectorial delta-lognormal model recently proposed to describe 2D movements can successfully simulate these phenomena. Although the power law has been found to be a good predictor in many experimental conditions, a few experiments have shown that the law does not apply to all graphic movements. Using the vectorial delta-lognormal model, the conditions under which a 2/3 power relationship can be observed are presented and the reasons why it does not seem to be verified for more general handwritten patterns are highlighted.
Plamondon
R
R
Laboratoire Scribens, Ecole Polytechnique de Montréal, Département de génie électrique et de génie, informatique, Québec, Canada. rejean.plamondon@mail.polymtl.ca
Guerfali
W
W
D001696:Biomechanical Phenomena; D003198:Computer Simulation; D006236:Handwriting; D006801:Humans; D009048:Motor Skills; D009949:Orientation