[atoav]

1. Tell them what you'll tell them

2. Tell them

3. Tell them what you told them

The key is that 1 and 3 shall have a suitable proportion of length to 2. Bad presentations just rattle down the index point by point. That sucks. The introduction is there to tell them what they will hear, some of the context needed to understand it and why it matters. It is best to see this as a way to make the crowd perceptible for the actual content, a bit like everything that happens at a good restaurant before the main dish is served.

This doesn't mean you need to give away the most interesting bits (results) in the beginning. But it would be good to tease them a little by focusing on the question, or surprising factoids that emerged through the research. Ask yourself the question whether the introduction serves the middle part and if it does not, adjust it or remove it.

In the end there are infinite ways to structure a presentation, the most important bit is to know the purpose of each part and then ensure the part fullfills it.