Two grades of LLDPE were analysed by a number of methods for fractionation and molecular structure determination (molecular weight, branching density). Methods used were: preparative fractionation according to comonomer content (TREF) and molecular weight (solvent - non solvent), CRYSTAF, SEC, SEC-FTIR and NMR. We explore different ways of combining and processing data to obtain two and three dimensional results. Methods to correct for chain end effects in and construct bivariate distributions from preparative TREF + SEC + NMR data is presented. The methods studied have different drawbacks and advantages. Preparative TREF + SEC + NMR and SEC-FTIR provide most information relative to the labour requirement. In general, the most complete information is obtained from combined interpretation of results from different methods.