I am writing a University Dissertation proposal on Big Data. I have recently received my feedback and while there are good, constructive points one of the main issues in the marking is it is "too descriptive". I do not understand what this means really, when we are talking about a literature review how can it not be descriptive - you are talking about what has already been found.
The exact feedback is:
Your literature review is overwhelmingly descriptive in character and its needs more of a critical edge, evaluating the main contributions to the literature. Having a critical edge is essential, if you want to achieve a high mark in the final dissertation.
So the question is: What is descriptive writing and what is critical writing, preferably with examples.