A brief account of some aspects of powder pattern analysis has been given. The emphasis has been on the Rietveld method structure refinement and analysis for single phase or multiphase materials comprising phases of known crystal structure. Major application of the Rietveld method is that of refining crystal structure parameters in materials intended to be single phase. Use of the Riveted method in quantitative phase analysis is finding increasing application. The improved accuracy which is obtained during this method may prove useful in phase diagram determinations based on the lever rule. The formal use of the quantitative phase analysis algorithm should also prove useful in diffraction studies of reaction kinetics, for a knowledge of the amount of each phase at any particular time is what is needed to establish the kinetics of a solid state reaction. The use of the non-structural parameters from Riveted to obtain information on texture, crystallite size and strain is probably less well established than quantitative phase analysis. Despite the existence of older methods and the possible development of new methods the analysis of powder diffraction data, the importance of the Riveted method for the analysis of these data is assured well into the future.