1. Make clear that the 'public option' refers unambiguously to a type of health insurance, and not the actual provision of health care services by the government.
2. Make clear that by "public", you mean "government".
3. Avoid using the term 'Medicare' when referring to the public option.
4. Make clear that the public option is, in fact, an option, and that private insurance is also an option.
5. Ask in clear and unambiguous terms whether the respondent supports the public option -- not how important they think it is.
"I would strongly urge people to cite the Quinnipiac or Time/SRBI polls when making reference to public sentiment on the public option. Not coincidentally, these come up with broadly similar results, showing between 56 and 62 percent in support of the public option, and 32 to 36 percent opposed. The other polls run the gamut from slightly to deeply flawed." — Nate Silver