How to read effectively a research paper? I am a student and I have been assigned to read a research papaer in the robotics field, understand it, elaborate it and write an essay about it. I have never done something similar, so I am a little bit lost. 

How should I read a research paper in order to do this? Is there a particular way of reading a paper or I just start from the top and follow the order of the pages? And is there an effective way to elaborate it?

Thanks in advance.
Read it from top to bottom, try to understand everything in it (that is, do the math on your own and check that you arrive at the same results), and try to write the essay without looking much at the paper.

At my department, we offer a course like this and the most common reason for bad grades are students who just copy-paste selected paragraphs from the paper.