What data science can’t predict

Many may be shocked that Nate Silver didn’t accurately predict the outcome of the US election, getting some of the key states wrong. If you don’t know who Nate Silver is, in short, he is a data geek (he hates the term data scientist) who has gained fame from correct political and sports predictions, bringing predictive analytics into the forefront of election coverage. He originally stated that Donald Trump had only a 2% chance of even winning the Republican nomination in the first place. One must remember that all of these predictions are based on predicted probability. 

 FiveThirtyEight.com's last prediction map for the 2016 US election

FiveThirtyEight.com's last prediction map for the 2016 US election

You can think of this like a weather forecast. If it is only 30% chance of rain on any given day, it doesn’t mean it won’t rain that day. It simply means that the day is more likely to not rain than to rain. This is perhaps a bad example as predicting weather is infinitely easier than predicting human behavior. And predicting weather is not easy. 


Nate Silver’s website, fivethirtyeight.com predicted Clinton had a 55% chance of winning North Carolina. Trump took the state. Would you take an umbrella if someone told you there was a 55% chance of it not raining that day? Probably, because these percentages are far from certainty. These were the same percentage chances given for a Clinton win in Florida. As of 98% of votes having been counted, Trump is ahead of Clinton by 128,630 votes, far less than votes for a third party candidate. 

 CNN Florida Election R

CNN Florida Election R

In short data science can’t predict everything. It has the most trouble when human emotions are involved, as they are during an election. If data scientists could predict everything, we probably would all be rich, own an island, and be living the high life having accurately predicted all stock market movements. Unfortunately the stock market, like an election, is driven primarily by emotions, and, thus, not accurately predictable.

 CNN Election Results

CNN Election Results

When you look at the US election results, don’t blame the analysts for predicting that America would come to its senses. Don’t lose faith in analytics, as they weren’t as far off as the outcome would suggest. Analytics uses logic, and illogical behavior cannot be accurately predicted.