  We present a method of testing for the presence of energy dependent
dispersion in transient features of a light curve. It is based on minimising
the Kolmogorov distance between two cumulative event distribution functions.
The unbinned and non-parametric nature of the test makes it particularly
suitable for searches of statistically limited data sets and we also show that
it performs well in the presence of modest energy resolutions typical of
gamma-ray observations (~20%). We illustrate its potential to set constraints
on quantum-gravity induced Lorentz invariance violation effects from
observations by the current and future generation of ground-based gamma-ray
telescopes.
