Handwriting quality is commonly evaluated off-line using either subjec
tive or pattern recognition techniques based on the static final outpu
t. Skilled performance is characterised in terms of legibility and as
a minimisation of spatial variability. However, these techniques are s
ubject to error, and provide little information about the underlying d
ynamics producing the movement. This study employed temporally sensiti
ve techniques to investigate the relationship between spatial (i.e. le
gibility) and the kinematic (i.e. dynamic) aspects of handwriting prod
uction. Each of 18 adult subjects (7 male, 11 female) wrote the pseudo
-word MADRO-NAL 10 times in their natural cursive handwriting. Horizon
tal (x), vertical (y) and pressure (z) coordinate data were collected
using a Wacom 1212-R graphics tablet controlled by a laboratory comput
er. Spatio-temporal aspects of the x, y and z velocities of the stylus
were analysed both between trials and within subjects using coherence
analysis. Subjects previously rated as good handwriters by three inde
pendent judges displayed a greater degree of temporal consistency than
the less proficient writers. The results showed that spatial inconsis
tencies are related to dynamic variability and demonstrated that the m
ethodology employed can provide a useful tool for the quantitative ass
essment of handwriting quality. (C) 1997 Elsevier Science B.V.