Public speaking is a different kind of influence than your normal everyday life.
In your normal everyday life you may need to influence a person or a small group of people that you are interacting with. Maybe it’s for a project that you are involved in, maybe it’s for a job interview, or even simply for rapport.
Since you are interacting closely with them you can pretty much see and feel every reaction like you are used to. You can notice it almost immediately as something feels off.
And of course, you have a lot of practice opportunities since we all tend to interact with people on a daily basis.
Public speaking tends to have some differences even if the underlying principles are the same.
First, you need a stronger projection. If you are influencing from a stage or from a center position to a large crowd/group, then you need to be projecting a lot stronger, than if you are only interacting with 2 or 3 persons.
It’s only logical if you think about it. You want your energy to reach everyone, not just the few persons towards the front. The may have the stronger impact anyway, but you want to reach everyone.
For that, you need a stronger projection than normal.
Secondly, while on a small gathering you can quickly assess everyone, in public speaking for a large gathering this is harder to do… however… it’s only a different skill.
Instead of feeling everyone individually, in public speaking you are feeling everyone as a crowd. It will be very hard to feel 100 people individually, but you can feel the group as a whole.
It’s a different skill, but the same principle.
Thirdly, if you want to influence most people in the crowd you need to simplify your objectives. Both in the quantity of what you want to get, as well as in the actual message.
One simple, powerful message is better than 20 messages.
20 messages won’t come across in a crowd of people. One of them yes.
Then the actual message, must be quite simple. The complexity is reduced to the lowest common denominator of the crowd. It’s one way to make sure everyone understands.
That’s the power of the TED talks. Usually, it’s one very clear message.
Those are the main differences, although it could be expanded much further.