An academic presentation is not a monologue. Nor should we advise or preach to the audience. A good presentation will provide a clear statement of an issue and the arguments for or against it. To avoid the pitfalls of monologues and the temptation to preach, you must know what you are doing. The presentation varies with respect to the type of content you have. For instance, if you plan to introduce a debate, you won’t be necessarily making any novel argument. However, you are expected to comment on the debate. The following table presents a rough classification of the types of presentations and the audience's expectations.
Tips: The Oneliner
Try formulating the main theme/thesis of your presentation in one line. If you fail, you may not have clarity on what you are going to do. That is an indication that most probably you will waste everyone’s time and possibly embarrass yourself. If you embarrass yourself and waste everyone's time for a few presentations, people will stop engaging you. That is not good.
It is possible to impress an audience with an impeccable performance of a carefully crafted gobbledygook. However, always expect an outlier to call a spade a spade. Please note that I haven’t commented on the manners of the presentation. It is always a good idea to have a written document for the presentation. However, reading out a text word by word is not a good presentation. Check John Norton's useful suggestion at the end of the page here.