Functional structure in sentences: A performance analysis

Two experiments are reported which attempt to define the groupings of component words within sentences which subjects have committed to memory. The structural groupings are indexed by judgement latencies for pairs of words and these serve as the input matrix for a hierarchical clustering (HC) analysis. It is concluded that when subjects make judgements concerning the forward order of pairs of words, the latencies imply the presence of a hierarchical organization. Although the tree structures obtained do not follow in any detail the surface structures of the sentence types in either experiment, nonetheless when constituent analysis indicates no difference it is accompanied by identical performance structures, and when a surface distinction is called for, an appropriate difference is found in the tree diagrams produced by cluster analysis. Deep structure differences involving the rearrangement of component words are not found in the hierarchical structure subjects imposed. The pausing patterns followed by subjects when reading the sentences are shown to relate to the structural diagrams generated by the HC analysis.