Final answer:
The worst kinds of informative presentations occur when the speaker lacks clarity and organization.
Step-by-step explanation:
The worst kinds of informative presentations occur when the speaker lacks clarity and organization. This can happen when the topic or claim is unclear and unsupported with credible evidence. The writer's ideas are also unclear and disconnected, resulting in insufficient or inappropriate transitions. Additionally, the use of media and visual aids may be missing or contribute little to the presentation.