Final answer:
An effective informative speech thesis should have a clear focus, demonstrate oral fluency, and appeal to the audience's intelligence and sympathies. It also includes providing evidence, articulating concepts accurately, and presenting an organized speech.
Step-by-step explanation:
An effective informative speech thesis should have several key traits. Firstly, it needs to have a clear focus and purpose that guides the speech's direction. It should also demonstrate oral fluency to ensure that the delivery is smooth and easily understood by the audience. Moreover, such a thesis needs to appeal to the audience's intelligence and sympathies, making the information presented both interesting and relatable. To achieve these objectives, one must provide evidence supporting the thesis, correctly articulate concepts, and organize the speech like an expository essay. An effective thesis statement should also show the speaker's intent to meet or challenge conventional expectations in a rhetorically effective way. For instance, a purpose statement might convey the intent clearly, such as 'By the end of this presentation, my audience will better understand the impact of plastic waste on the ocean and the world.