While at first the inclusion of contradictory information might seem strange, doing so builds listeners' and increases a speech's

- Trust; persuasiveness.

Explanation:

Contradictory information is also known as 'counterclaims' that serve to propose the rebuttal or denial to the original/central claim of the speech. However, it seems strange as there is a fear that it might go against the validity of the central argument of the work but the chief aim is to build the listeners' 'trust' that the author presents an objective claim(by analyzing both the perspectives). This leads to enhance the credibility of the claim and improve the 'persuasiveness' of the speech that would assist in convincing the audience more effectively. Therefore, 'counterclaims' are deliberately employed by the authors to uplift the reliability of their speech which is negated by sufficient evidence to establish the validity of central argument/claim.

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