In addition to sampling error, the practical difficulties of conducting any survey of voter opinion on an election day, like the reluctance of some people to take time to fill out the questionnaire, may introduce other sources of error.

In addition to sampling error, which is a statistical function of the polling technique, practical difficulties of conducting a survey can introduce error in the findings.

In addition to sampling error, the practical difficulties of conducting any opinion survey may introduce error into the poll.

In addition to sampling error, the practical difficulties of conducting any survey of voter opinion on caucus day, like some voters changing their minds after they enter the caucus, may introduce other sources of error into the poll.

In addition to sampling error, the practical difficulties of conducting any survey can introduce other sources of error into the poll.

In addition to sampling error, the practical difficulties of conducting any survey of voter opinion on Election Day, such as the reluctance of some voters to fill out questionnaires, may introduce other sources of error.

In addition to sampling error, the practical difficulties of conducting any survey of voter opinion at polling places, like the reluctance of some voters to take time to fill out the questionnaire, may introduce other sources of error into the poll.