The methodology

THE NDTV-Frontline-CSDS post-poll survey was carried out in all the four States that went to the polls. It was not held in the Union Territory of Pondicherry. A post-poll survey is different from an exit poll in that it is conducted at the respondents' home after the polling process is over.

It allows researchers to pick a truly representative sample by following the rigorous procedures of random sampling. It also provides an opportunity to quiz voters in detail about their opinions and attitudes. It is regarded as the most reliable method of finding out how and why the voters voted the way they did.

The CSDS team of 294 researchers began interviewing voters on the evening of May 10, as soon as polling came to an end. All the interviews were completed within 24 hours, well before counting began. The tables present the detailed break-up in terms of Assembly constituencies, polling stations and the respondents sampled for this survey. In order to encourage transparency in reporting surveys, the social profile of the respondents and any discrepancy between survey findings and the actual outcome are laid out here. The Assembly segments were sampled following stratified random sampling techniques in order to ensure fair representation of all the regions and categories in each State. Three polling booth areas were selected in each sampled Assembly segment by circular means of random sampling. The same procedure was employed to select respondents from the electoral rolls of the sampled booths. No substitution was allowed if the sampled respondent was not available. All the interviews were carried out by trained researchers at the respondents' home. The question about who they voted for was asked by giving them a dummy ballot, and it was ensured that their choices remained secret.

In each State, the survey was coordinated and supervised by a senior political scientist: Dr. Sandhya Goswami in Assam, Prof. G. Gopakumar in Kerala, Prof. G. Koteswar Prasad in Tamil Nadu, and Dr. Amiya K. Chaudhury in West Bengal. The central team that analysed the data included Prof. V.B. Singh, Director, CSDS, and Sanjay Kumar, Kanchan Malhotra, K.A.Q.A. Hilal, Himanshu Bhattacharya, Bhaskar Jha, Kumud Ranjan Singh and Subhra Ranganathan, all from the CSDS.

The CSDS will answer any query about its surveys at lokniti@vsnl.com