The principle that a given end state can be reached by many potential means. Thus, in geomorphology, this term indicates that similar landforms might arise as a result of quite different sets of processes. For example, Cruslock et al. (2010) Geomorph. 114 note that different erosion mechanisms—in this case, wave action and ice scour—have produced similar shore platforms in Sweden and South Wales in the UK. Thus from the landform alone, without additional evidence, it might be difficult to identify the particular set of causes or to differentiate different feasible causes.