You can never prove the future, but most often all people are really looking for I find is some sort of logical proposition.
If you can get people to accept A and then show how A > B > C> > D you can get people on board. When I do my strategy presentations, there is no data, no charts, no pseudo science or “results” just a thoughtful analysis that breaks down some possibilities in the market and shows opportunities and the logical conclusion to following certain assumptions.
By taking a step by step approach I find it is a lot easier to convince people than the big jump of logic most designers find easy to understand.
Dunno if this makes any sense. Speaking in such generalities it’s hard to explain.
R