Dallinger, Carl A.||Tucker, Charles O.||Crawford, Paul K.
M.A. (Master of Arts)
Department of Speech
The purpose of this study waas to investigate experimentally the effect a speaker's use of substandard grammar has on his credibility and the general effectiveness of his speech as indicated by audience ratings of these factors. Three versions of a speech were constructed. Version I contained no substandard gramatical usages, Version II contained 35 substandard usages, and Version III contained 70 substandard usages. Two speakers each recorded the three versions of the speech. Six classes, a total of 77 students in four classes of Fundamentals of Speech at Northern Illinois University and a total of HI students in two classes of Basic Speech at Rock Valley Junior College during the summer of 1967, were subjects for the experiment. Each class was randomly divided into three groups; each group heard one version of the recorded speech and evaluated the version of the speech that they heard on semantic differential scales containing items measuring speaker credibility and general effectiveness. The criterion measure was based upon the differences between the n*an scores of the three treatment groups in each class. The .01 level of confidence was established as the level for significant differences. Three null hypotheses were tested: (1) Increasing the amount of substandard grammatical usage in a speech will not significantly lower the audience ratings of speaker credibility. No significant differences were found between the mean scores of the three treatment groups on the credibility scale as rated by the subjects in six classes of beginning college speech. This hypothesis was retained. (2) Increasing the amount of substandard grammatical usage in a speech will not significantly lower the audience ratings of general effectiveness of the speech presented. No significant differences were found between the mean scores of the three treatment groups on the general effectiveness scale as rated by the subjects in six classes of beginning college speech. This hypothesis was retained. (3) No correlation will exist between the ratings given the items measuring speaker credibility and the items measuring general effectiveness. Using the Pearson product-moment coefficient of correlation formula, a correlation of +0.68 was obtained from ratings on the scales of general effectiveness and credibility by 77 subjects at Northern Illinois University, and a correlation of +0.73 was obtained from ratings on the scales by HI subjects at Rock Valley Junior College. Both of these group correlations were high enough to indicate a need to investigate whether the scales of speaker credibility and general effectiveness used in this experiment measure discretely different aspects of speaking. This hypothesis was rejected. Although this study does not provide conclusive evidence, it does have important implications for the study of standards of language usage in the classroom. The findings of this study suggest that audiences are not as sensitive to subtandard usages in speaking as speech teachers are prone to believe.
Hershey, Georgia, "The effect of substandard grammatical usage on audience ratings of general speech effectiveness and speaker credibility" (1968). Graduate Research Theses & Dissertations. 5566.
viii, 84 pages
Northern Illinois University
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