The fourth characteristic of big data—veracity, which was added later—refers to the need to validate or confirm the correctness of the data or the fact that the data represents the truth. The sources of data must be verified and errors kept to a minimum. According to an estimate by IBM, poor data quality costs the US economy about $3.1 trillion dollars a year. For example, medical errors cost the United States $19.5 billion in 2008; you can refer to a related article at http://www.wolterskluwerlb.com/health/resource-center/articles/2012/10/economics-health-care-quality-and-medical-errors for more information.

The following link provides an infographic by IBM that summarizes the four V's of big data: https://www.ibmbigdatahub.com/infographic/four-vs-big-data.