Final answer:
The text does not specifically recommend calling people at random during long presentations but does suggest engaging the audience with various interactive techniques. Emphasis is placed on preparation and varying methods of interaction to maintain attention. Technology can be used to enhance and ensure dynamic delivery, and it should be tested beforehand.
Step-by-step explanation:
The text does indeed recommend engaging audiences in various ways during long presentations, but it does not specifically mention calling on people at random as a recommended technique. However, it does suggest multiple techniques to engage audience members, including word clouds, small group discussions, and live polls. These techniques are all interactive and can serve to maintain or regain audience attention, which can be crucial, particularly during longer segments where attention may begin to wane.
Additionally, the text emphasizes the importance of preparation before speaking to the public, refuting the idea of "winging it" as being an ineffective strategy for speech delivery. This is because, according to some sources, live adult audiences tend to lose attention after about 20 minutes, and even quicker for younger audiences. Thus, for more effective engagement, varying the methods of interaction throughout the presentation is key.
One must also consider the dynamic delivery of their content. The text recommends using technology to enhance communication, ensuring that any media used does indeed engage the audience and contribute to a dynamic presentation, which could be especially helpful during longer talks. Finally, it is essential to test technology before the presentation to prevent any mishaps that could disrupt audience engagement.