According to Sarid Institute's motto "Turning information to power", the main role of political surveys is to supply information to the candidate and his team on the campaign.
The information which is the main result of the surveys serves the candidates and their aids in order to understand what the public wants, instead of trying to guess it.
Sometimes the findings will surprise and some times they will corroborate the intuition already present, but once there is reliable and up-to-date information at hand, you start to walk on stable ground and there's no need to guess. The information turns into power since the candidate knows how to prepare for the campaign and how to treat the different issues at hand.
There are a number of surveys which can be of use to political candidates:
Benchmark: Used to give a wide picture about the public's opinion of the candidate, his party, their actions, other candidates, and the issues on the public's mind. The survey is usually preformed a year before elections, and it is very (40-50 questions).
Public Awareness: The goal of this survey is to measure the public's awareness and attitude towards the candidate and to rival candidates, effectiveness of activities, is the public's opinion positive/neutral/negative towards the candidate? Has the public's opinion changed from the benchmark survey? What new messages should be raised? This survey is usually conducted 6-8 months before the elections, and includes about 30 questions.
Tracking and eva luating Chances: In a medium length, this survey includes about 25 questions and its aim is to measure the public's awareness, what messages should be cleared, and what are the chances of the candidate. This survey should be conducted 2-3 months before election day.
Survey for Updates and pre-GOTV (get out the vote) Activities: This is a medium-short length survey (about 15 questions) and its aim is to gather up to date information about the public's opintion, the effectiveness of the campaign so far, and to collect operative data towards the "get out the vote" activities. The questionnaire should include questions regarding rival candidates, should political deals be set into motion, how would the public accept such deals and so on.