  Norris et al. (1994) report that the temporal structure of faint gamma ray
bursts is longer than that of bright bursts, as expected for time dilation in
the cosmological models of burst origin. I show that the observed trends can
easily be produced by a burst luminosity function and thus may not result from
cosmological effects. A cosmological signature may be present, but the tests
Norris et al. present are not powerful enough to detect these signatures.
