 By contrast, within the relational view an object can only be identified as datum when it is viewed as having value as evidence. Evidence becomes a category of data identification, rather than a category of data use as in the representational view (Canali 2019). Evidence is thus constitutive of the very notion of data and cannot be disentangled from it. This involves accepting that the conditions under which a given object can serve as evidence—and thus be viewed as datum - may change; and that should this evidential role stop altogether, the object would revert back into an ordinary, non-datum item. For example, the photograph of a plant taken by a tourist in a remote region may become relevant as evidence for an inquiry into the morphology of plants from that particular locality; yet most photographs of plants are never considered as evidence for an inquiry into the features and functioning of the world, and of those who are, many may subsequently be discarded as uninteresting or no longer pertinent to the questions being asked.