The microstructure of ring-opened metathesis polymers formed from cyclic olefins may be defined in terms of tacticity as well as the distribution and ratio of cis/trans double bonds; the current availability of a wide range of catalyst systems allows almost infinite variation of these microstructural features. A methodology is described whereby the tacticity of polymers formed from bicyclo[2.2.1]heptene (norbornene) and derivatives, using these catalysts, may be determined by C-13 and H-1 n.m.r. spectroscopic techniques.