This talk was held at the 11th meeting on April 7 2014 by Karolina Alexiou.
Analysis of big data is useless (and a lot harder to sell) when you can't measure whether the resulting insights are correct. In order to develop sophisticated data analysis methodologies tailored to your particular use-case, you need to be able to figure out what works and what doesn't. It is crucial to gather data independently to your analysis (ground truth) and compare it to your results using the correct metrics and account for biases. The sheer volume of data means that you also need to have a strategy for slicing and dicing the data to isolate the really valuable parts, and also, a keen eye for visualization so that you can quickly compare methodologies and support the validity of your insights to third parties.