Some ideas in explanatory speeches may run contrary to what intuition tells us. Consider the polio vaccine, which was tested in 1952 and used an injected dose of an inactive (essentially, dead) polio virus. The notion of using something that makes people sick to prevent people from getting sick is counterintuitive. Imagine how difficult this must have been to explain to patients and worried parents at the time.

If you are giving an informative speech on how vaccines work or another counterintuitive idea, you might want to design your talk around transformative explanations. Transformative explanations are designed to help speakers transform “theories” about phenomena into more accepted notions. For your speech on vaccines, you might describe how, by exposing the body to a similar but benign virus (like the dead polio virus), a vaccine essentially teaches the body to defend itself against a specific disease.