Yesterday I had the pleasure of sending off another paper to be published in one of our esteemed professional journals. This is the second time I have sent this paper in, and I'll probably end up doing a third version before it is finished.
This is not unusual. Most scientific papers go through a process called peer review. Let's say that Professor Jane Q. Astronomer has discovered Star Lucy is made out of diamond, an exciting discovery. After doing the appropriate analysis, Professor Jane writes a paper and sends it to an astronomy journal. The editors at the journal then pick another astronomer who works on similar research to be the peer reviewer. If this astronomer agrees to do the work, he will get Professor Jane's paper and read it through carefully and write comments and concerns on the paper.
Sometimes the comments can be minor, such as "Professor Jane forgot to mention that Star Lucy was first discovered by Lennon, McCartney, Harrison, & Starr (1967). She should mention that." Or "Professor Jane got the coordinates of the star slightly wrong, it appears to be to the northeast by a slight amount."
Other times comments are much more serious, such as "Professor Jane is wrong to say that the star's spectrum shows it is made of diamond; the spectrum is really closer to that of cubic zirconium." Or, on rare occasions, "Professor Jane is aparrently unaware that Professor Billy Bob published this same analysis in a paper three months ago. This paper presents nothing new."
Once comments have been made, the paper and comments are sent back to the author. Professor Jane now should address each of the issues raised by the reviewer, whether it be fixing typos, adding missing information, or more clearly statnig her case. If Professor Jane disagrees with the reviewer on a point, then she must explain why the reviewer is mistaken. When she is finished, the paper is sent back to the same reviewer for his opinion on the revised version.
Often, after this second look, the paper is good enough to be published with a small number of additional, minor revisions. But sometimes these papers can take many iterations, and other times the paper has serious enough flaws that the journal rejects it altogether.
So, here's hoping that this second iteration is good enough for my reviewer!