Abstract
Arguments are developed to show that a factor termed preservation potential could bias the operational data of palaeocurrent analysis, and hence any palaeogeo‐ graphical inferences that are drawn. Flow systems and their directional sedimentary response elements are hierarchically organised in the geological present. A flow system can therefore be characterised (within the limitations imposed by preservation potential) only by reference to all the ranks of sedimentary structure generated therein. The operational rock structures generally employed in palaeocurrent analysis are usually low‐ranking and subject to several sources of variance.