SA Decides poll methodology
The “SA Decides” Election Tracker is the largest and most definitive independent sample survey for the 2014 elections.
It is conducted by independent international polling agency C-Voter, an internationally renowned name in the field of election predictions.
In 2012 US presidential elections C-Voter along with Ipsos was ranked among the most accurate pollsters by New York Times’ acclaimed commentator and statistician Nate Silver. The difference between Ipsos and C-Voter projections in the US presidential elections was less than 1% votes.
This particular poll is not a random probability sample. It is a convenience poll carried out by trained South African researchers travelling with ANN7 reporting teams across all nine provinces.
There is one team of five personnel travelling in each province, interviewing people on the ground with a structured questionnaire.
The total team strength is 45 and covering a structured route giving maximum geographic coverage to the poll. Their travelling dates and routes are well publicised by ANN7 and its sister publication The New Age.
The survey results are based on face-to-face interviews of 5125 respondents across all nine provinces between March 9-25. The data is weighted to known census profiles.
The convenience polls don’t carry the margin of errors as they are not as scientifically designed as a thorough random probability sample. However, our previous experience in such operations gives us confidence that our estimates will be within the 5% margin of error at national level for the Vote Share projections.
We are using our proprietary algorithm to calculate the provincial and national vote share based on the split-voting phenomenon.
We have used this algorithm to correctly predict many elections across many democracies.