<div style='font: 12pt "Cooper Black"; text-align: left; '>most series authors will introduce things early and then refer to it in later books making the reader go, "oh yeah i remember her mentioning that (person, place, etc)."
Rowling, on the other hand, just makes stuff up on the spot every book and its annoying. For example, in the latest book there are these tests called O.W.L.S that 5th years have to take and she makes it a big big deal like the SAT's or something. Only thing is, why has she never mentioned these tests before in any of the other books? There were older characters in the last books that would have been in their 5th year even if Harry and friends were not. A good author would have had one of the Weasley brothers mention the O.W.L.S. in like the 2nd or 3rd book in one sentence or so and then have Harry and friends deal with them in the 5th. She did successfully do this call back with the room where D.A. practice their Dark Arts but this is the ONLY time i think i can remember her doing it. There are also, now, things called N.E.W.T.S. in the 7th year that she just springs up, i'm sure in the 7th book she will use them again, but its still funny how in 4 years at this school this is the first time the reader hears about this stuff when they are considered so important.
While she did grow Harry up in the 5th book, she did it too fast. He is all teenager in this one, attitude and all, while in the 4th he showed no signs of it whatsoever, where is the progression? She also still uses the "You're going to get expelled!" thing too much. By now Harry should have been expelled like 800 times, you would think he would learn that he can do what he wants and wont get expelled, but instead she still makes him always scared of getting kicked out of Hogwarts.
All in all, though, i do like reading them. I guess i am being nit-picky.</div>