Analogy and comparison are central components of human cognition. The elements or traits – including their relationships, such as evolutionary or supply chains – between the source and the target are mapped or aligned in a comparison. A trait has salience for comparative purposes based on the degree to which it classifies an object, that is, its diagnosticity. Targets (questioned items) are more salient than sources (known items) and require additional evaluation, like suitability. For comparison to be possible, the traits must be structurally consistent (have a one-to-one correspondence), have common relations (context), and have systematicity (all of the higher-order “constraining relations”)
