The local variation rates of a chaotic dynamical system provide a mean
s of stroboscopic observation at adjustable tames which minimize the s
econd variation of the coordinates. The sequence of strobing intervals
carries global information on the dynamics, yielding a suitable indic
ator which discriminates deterministic from stochastic signals. Due to
the adaptive nature of the strobing process, the characterization of
this indicator requires a computational effort much smaller than stati
stical methods.