Data is useless, unless processed and some useful information is extracted from it. For the same reason, a data scientist not should only be able to clean data and extract data , he should essentially produce some useful information out of heaps of data. With that being said, another proposition that you might have heard but may not have completely understand is that "Data Science is a multi disciplinary field" . To be effective one has to juggle around many subjects. It employs techniques and theories drawn from many fields within the broad areas of Statistics and Computer Science. C omputer Science , in particular from the sub-domains of Machine Learning, Classification , Databases, visualization and Big data technologies. Data scientists use their data and analytical ability to find and interpret rich data sources; manage large amounts of data despite hardware, software, and bandwidth constraints; merge data sources; ensure consist...