Abstract
Following a brief review of the physics by which X-ray scattering can be made surface sensitive, we will discuss some details of the effects that interfacial roughness and asymmetry of interfacial profiles have on measurements of X-ray specular reflectivity. Experiments related to these effects, including study of the width and interfacial roughness of the liquid/vapour interface for H2O, superfluid 4He, thin wetting films of cyclohexane on Si, and metallic liquid Ga, have been reviewed elsewhere.