Pravesh Debba of the CSIR says accuracy is key in predictive election results methodology. SABC News
The SABC and the CSIR has relied on accuracy and speed to bring television, radio and digital audiences elections results and predictions after every voting day since the two organisations formed a partnership in 1999.
To best illustrate accuracy for 2019 voters, the CSIR showcases a local government election result in 2016.
Typically the prediction results at a municipal level are less accurate than those at a national or provincial level since one is working with a smaller sample of voting districts. Overall, however, the 2016 municipal predictions for the metros’ PR votes proved to be a great success.
For these municipal elections, the model was able to predict, at a very early stage on Thursday morning 4th August 2016 (5am), when there was still a great deal of uncertainty about where things would end, the final vote share for all the major parties in the metros of interest to within 1.9% of the final outcome.
In the case of Tshwane, however, the model did not pick up until very late in the counting process that the DA would end up winning the largest share of the metro, although this winning margin was extremely small.
The most impressive early prediction was for eThekwini – even though no voting district results had been reported from this municipality (due to technical issues) the CSIR prediction model, using results from the rest of the province, determined not only that the ANC would retain its control of the metro but got within 0.3% of the final result for the top 4 parties (see Table 2 below).
The prediction for Johannesburg was also very accurate, particularly since the first prediction released to the media at 5am on Thursday morning, after 13% of Johannesburg voting districts had been declared, ended up being within 0.4% of the final result for both the ANC and DA, while the actual counts kept showing a very different result until late on Saturday afternoon when the final count was declared (see Table 2 below).
