A case study of anomaly detection: shallow semantic processing and cohesion establishment.

Although the establishment of a coherent mental representation depends on semantic analysis, such analysis is not necessarily complete. This is illustrated by failures to notice the anomaly in questions such as, "When an airplane crashes, where should the survivors be buried?" Four experiments were carried out to extend knowledge of what determines the incidental detection of the critical item. Detection is a function of the goodness of global fit of the item (Experiments 1 and 2) and the extent to which the scenario predicts the item (Experiment 3). Global good fit appears to result in shallow processing of details. In Experiment 4, it is shown that if satisfactory coherence can be established without detailed semantic analysis, through the recruitment of suitable information from a sentence, then processing is indeed shallow. The studies also show that a text is not understood by first producing a local semantic representation and then incorporating this into a global model, and that semantic processing is not strictly incremental.