The validity of cognitive distance in oral and written discourse.

Oral and written discourse samples of adolescents with closed head injury (CHI) and controls were analyzed to determine if efficiency and coherence measures changed as the length of their picture descriptions increased. The hypothesis was that as ideas were elaborated, the number of words used to express an idea would increase and the conceptual connectedness of ideas would decrease. This research study supported this expectation for efficiency in normal oral and written discourse but not for the discourse of participants with CHI. Further, the efficiency measure significantly differentiated the writing and speaking of the two groups as the picture descriptions were elaborated. Coherence ratings did not distinguish the development of discourse within or between groups