Diagrammatic Reasoning about Allen's Interval Relations

We explore different ways in which a computational model of diagrammatic reasoning can capture imagery experiences which subjects reported in an experiment on spatial reasoning. The algorithmic reconstruction of this particular reasoning process suggests that computational models of diagrammatic reasoning should be formulated at different levels of abstraction. Four levels are distinguished – ordinal positioning, metrical positioning, pictorial merging and object depiction. Finally, consequences for the computational modelling of individual differences in imagery are discussed