Polls don't check electoral fraud

Re: "Opinion polls also a check on possible election fraud", Letters, March 9.

To state that "the purpose of exit polls, among other things, is to check for electoral fraud" is somewhat naive. The poll is not taken on every person leaving a polling station. That is an impossible task for any pollster. The exit polls are taken from the sampling of a few thousand voters after leaving the polling station.

This sampling is the statistical group that is crucial to its finding. If the group is unreliable or unrepresentative of the voting population, then the result would be wrong. The chief of Nida Poll gave credit to his interviewers for carefulness in vetting its sampling.

With that small number, it has no role in checking electoral fraud.

Songdej Praditsmanont

Bangkok