  We show that a suitable setting for comparison of the low-energy
representation for pion-pion scattering amplitudes, with dispersive
representation for these amplitudes, is provided by certain manifestly crossing
symmetric dispersion relations. We begin with a discussion of fixed-t
dispersion relations and discuss the origin of crossing constraints that arise
in this context when we consider resonance saturation with certain $l\geq 2$
states. We demonstrate that the approach advocated here does not require us to
enforce such constraints. Our results are contrasted with those from fixed-t
dispersion relations. We finally discuss the numerical import of our results.
