The Research 2000 Missouri Poll was conducted by Research 2000 of Rockville, MD from January 21 through January 24. It consisted of three samples.

A total of 800 likely voters who vote regularly in state elections were interviewed statewide by telephone. The margin for error, according to standards customarily used by statisticians, is no more than plus or minus 3.5 percentage points. This means that there is a 95 percent probability that the "true" figure would fall within that range if the entire population were sampled. The margin for error is higher for any subgroup, such as a gender or region.

Research 2000 also conducted two other samples; one of 500 Missouri Republicans likely to vote on Feb. 5 and the other was of 500 Missouri Democrats. Those polls were used to determine which presidential candidates were the party favorites among Republicans or Democrats.

The margin of error for those two samples is 4.5 percentage points.

For all the samples, those interviewed were selected by the random variation of the last four digits of telephone numbers. A cross-section of exchanges was utilized in order to ensure an accurate reflection of the state. Quotas were assigned to reflect the voter registration of distribution by county.