Traditional tabular sorting practices emphasize the differential importance of species within stand groups. Such a method orders (ordinates) the species while classi- fying stands, and by symmetry an inverse analysis will ordinate stands while classifying species. In this paper some methods of defining group structure which permit choice at any division between normal and inverse approaches are examined. One of these, the two-parameter method, also permits monotonic variation within groups, and in this case the choice of normal or inverse analysis is equivalent to a choice of classi- fication or ordination alternatives. Such an analysis is termed inosculate. In comparison with a quantitative information analysis, the two-parameter method provides a more detailed and informative representation, although the division procedure is monothetic. The establishment of dominance, constancy, and fidelity criteria is examined, and the environmental interpretation of species and stand groups attempted. While the analysis is computationally time-consuming for quantitative data, it is certainly very rewarding. Some alternative approaches permitting inosculate analysis are also briefly examined.

Ordination techniques seem hitherto not to have been applied to two problems of considerable botanical interest: (i) the ordination of a set of groups after a numerical classification, and (ii) the ordination of an asymmetric system. The botanical contexts in which these problems arise are discussed. It is shown that Gower's "principal coordinate analysis" can be simply extended to cover these two cases; computer programming requirements are minimal, and standard programmes are available for the Control Data 3600 computer.