Surveys have been widely used by politicians around the world as a way of monitoring the opinions of the electorate.

Surveys have been widely used by politicians around the world as a way of monitoring the opinions of the electorate.  Six months ago, a survey was  undertaken to determine the degree of support for a national party leader. Of a sample of 1,100, 56% indicated that they would vote for this politician.  This month, another survey of 800 voters revealed that 46% now support the leader.