Verbal Response Indicators of Conceptual Vagueness1

The plight of being caught without a needed word while speaking or writing is a common experience. A sudden lapse in memory or momentary confusion may underlie the difficulty. Or the problem may arise when a speaker, in the midst of expression, discovers he doesn't command the knowledge required to complete his gambit. This paper presents an analysis of the verbal behavior of the speaker or writer confronted with the immediate necessity to express himself while he struggles against one or more such handicaps. The key term in this analysis-vagueness-is defined here, after which evidence obtained in two correlational studies is reviewed and then recent experimental evidence reported. "Vagueness is a psychological construct which refers to the 'state of mind' of a communicator who does not sufficiently command the facts, knowledge, or understanding required for maximally effective communication," (Hiller, 1968). Vagueness is an internal stimulus condition principally determined by a performer's instant command of knowledge, by his motivation to communicate and by his own evaluation of imperfect success. Valid interpretations of vagueness research must give attention to situational parameters, such as: (1) the topic of the communication, its potential factual load and logical complexity; (2) the in-