although big data is very good at detecting correlations, especially subtle correlations that an analysis of smaller data sets might miss, big data analysis doesn't necessarily show causation or which correalations are meaningful.for example, examining big data might show that from 2006 to 2011 the United States murder rate was highlly correlated with the market share of internet explorer,since both declined sharply.but that doesn't necessarily means there is any meaningful connection between the two phenomena. data analysts need some business knowledge of the problem they are trying to solve with big data.