Final answer:
The student forgot to include a logical appeal or logos in her preview, which would use facts and evidence to make the argument more persuasive in conjunction with the emotional appeal she presented.
Step-by-step explanation:
A student created a preview that demonstrated benefits to the audience and included an emotion-evoking statement. From the details provided, what she forgot to include was a logical appeal, also known as logos. Emotional appeals, or pathos, can capture an audience's feelings, but convincing them often requires the balance of logos, which relies on facts, evidence, and a rational argument. Without this element, the preview may not be as persuasive as it could be because it lacks the substantiation that logical appeal provides. To create a more compelling and well-rounded argument, the student should consider incorporating a logical appeal through statistics, verified facts, or other forms of concrete evidence that support the merits of the proposal or idea.
An example of improving her presentation could involve addressing the direct impact of the proposition with data or case studies. Additionally, establishing credibility through ethos—the appeal to ethics—can also strengthen the persuasiveness of the presentation.