A Formula for Predicting the Comprehension Level of Material to be Presented Orally

Abstract

THE ABILITY to communicate is undoubtedly one of man's most valuable attributes. Communication may be simply defined as a process which allows an idea to be transmitted from one mind to another. Essential to the process are: (1) a mind to formu late the idea, (2) a method for transmitting the idea, (3) a mind to receive the transmission, to interpret the stimuli which it involves, and to recreate the idea in a form as nearly identical to the original as possible. Man has developed many systems for the carrying on of this process. There are pictures, songs, stat ues, written words, spoken words, eyebrows to be lifted, and shoulders to be shrugged. Of the many avenues available to him for communicating ideas, there is 1 i ttle doubt that the spoken word is most used by man. There are broadly discernable stages in lingu istic development. Language development may be thought of as a continuum, one extreme of which is characterized by a limited vocabulary and a simple grammatical structure, and the other extreme of which is characterized by an extensive vocabulary and a complex grammatical structure. If this as sumption is correct it should be possible to devise a method for predicting the general stage of language development which would be required by an individ ual if he is to understand any specific body of mat erial which is to be presented orally. A method for predicting the comprehension level of material to be presented orally would be of value to many people. Lawyers, radio broadcasters, pub lic speakers, preachers, and teachers would all welcome such a technique. As the average educa tional level of adult Americans is somewhere around the ninth grade, it would be futile for a radio an nouncer to advertise his sponsor's product in terms which could be understood only by a superior college graduate. Similarly, a teacher who explains to a third grade class in phrases which are unintelligible even to average children in the eighth grade is wast ing not only his own time but that of his charges as well. What is needed is a technique whereby a speak er can grade or evaluate material in terms of the comprehension level of those who are to experience its oral presentation. It is immediately apparent that the general prob lem of oral comprehension may be divided into two major sub-areas: (1) content factors, (2) delivery factors. The first of thesedeals with elements which are found in the material itself--variety and diffi culty of vocabulary, grammatical complexity and familiarity and interest of the general subject. The second deals with elements which depend primarily upon the person who delivers the material?dialect, enunciation, rate of delivery, and quality of the speaker's voice. As the scope of this article must be restricted to manageable proportions, its attention is directed to ward factors which are inherent in material per se. It undertakes to describe the derivation of a formula for predicting the comprehension level of materials | to be presented orally. This formula is based o n content factors and their relationships to the com prehension levels of specific audiences. The most logical method for arriving at the de I sired formula was obvious from the beginning: (1) identify a number of content factors which might in fluence the comprehension level of material to be presented orally, (2) as a criterion identify a body of material graded according to its understandabilit y by people at all stages of language development, (3) through the use of partial and multiple correlation technique, using the criterion proposed in (2) above a s the dependent variable and the proposed measures of grammatical complexity and vocabulary loading as independent variables produce a formula which would predict the level of language development re quired for comprehending any specific body of mat erial to be presented orally. As a matter of fact, that was the actual route followed in deriving the final formula. Many sticky problems were encountered on the way, however. There is not space to listthemhere, and a descrip tion of them and their solutions would add little light to this presentation. The identification of the content factors to serve as independent variables was a simple matter. As grammatical complexity is a f u n c tion s t r u cture rather than a function mode of delivery, content fac tors which had been found significantly related to difficulty in printed material might well be assumed to play a similar role with respect to material for oral presentation. As there was in existance a rather extensive literature pertaining to readability, a thorough study of this material was indicated. An analysis of each of twenty-one formulae for pred i c t ing readability revealed eight variable s which were