The electrical resistance of two iron-aluminium alloys, bordering on the composition Fe2A1, was measured at room and liquid nitrogen temperatures after inducing various states of order. By means of an analysis based on values of residual resistivity and of the temperature coefficient of resistivity, the influence of order on electronic factors in the conductivity, and on the perturbation of the lattice that produce scattering, were separately estimated. The freedom of conduction electrons diminishes as the order increases, and the decrease in low temperature resistivity associated with increasing order is due to the greatly reduced scattering potential. Those conclusions permitted a qualitative interpretation of the form of the anomalous resistance/temperature relation at high temperatures.