Positive stories. Everyone loves a heartwarming story. So when you could talk about something good that can happen, a challenge that was overcome and everybody was better off, or you did, in fact, live happily ever after. That's great. The real challenge though is, can you do it in a way that doesn't sound trite, cliche, boring, same old, same old, when you can deliver a positive story, but a slightly different twist. That's when it's powerful.
That's when it's going to be most effective. So the power of positive is very strong, but put a little creativity in it a little difference, and it's going to be even stronger. positive stories should be most of what makes up most presentations most of the time. Not always. If you're just giving presentations to alarm people about why they need to take A certain political action or there'll be catastrophe whether it's environmental or politically, you may have more negative stories, but in many cases business professional life, you do need to lean more heavily towards positive stories for maximum impact.