# Harry Potter: Books cf Movies

Everyone knows that the number of pages per book in the famous series by J.K. Rowlings increased over time, but was this increase steady? Was it consistent? The answer seems to be no.

Looking at this graph, is is probably more accurate to say that the early books were a certain length, around 400 pages or less, and the later books (4 through 7) were longer, around 700 pages. This may seem like a trivial observation, and it probably is. But it is important to understand the basic pattern of page length over time in this series before we explore the more important and deeper meanings of it all.

By the way, and this is a small digression, I had asked a while back about which Harry Potter movie disks would be the best ones to get in order to have a complete collection. At the time, I ended up buying this one:

It seems to have all the movie bits and some extra material as well. Then, more recently, I picked up the DVD/Blue Ray of the final movie, number 7b:

The reason this is interesting is that I never did see that movie in theaters, because it came out a few days after Julia left the country for an extended trip, and in sympathy for her pain of missing this movie’s opening, I refused to watch it until she returned. Meanwhile, the DVD/Blue Ray of the final movie, Harry Potter and the Deathly Hallows: Part 2, came out just a few days before Julia’s return. So we watched it yesterday.

Anyway, back to our analyses…

People seem to wonder, and comment, quite a bit about the relationship between these books and these movies. It might be useful to explore the basic pattern of this relationship. We might ask if the longer books yield longer movies, for instance. Does the number of pages in a Harry Potter book predict the number of minutes in the corresponding Harry Potter movie?

It does not take fancy statistics to examine this. The answer, simply, is no.

Ignore the one dot that is up and to the right. Looking at only the first seven movies, as book length goes up, movie length does not. The dot all by itself in the upper right is the combined length of the last two movies on the number of pages of the final book. (The seventh book in the series was made into two movies.) I could have split the book into two parts and regressed each of those parts on the appropriate movie length but since we can see that there is no relationship, that would not have been worth the work.

Finally, for completeness, we have this:

This just shows the variation across the series of seven books in movie lengths, with the runtime for the seventh book being a combination of the last two movies. The scatter plot above is, essentially, this bar chart and the first bar chart combined.

I have a few observations to offer, some of which were suggested to me by Julia.

To the extent that book length is higher in the later part of the series but the movie lengths mostly stay the same, we see a decrease in the degree to which the movies faithfully and completely represent the book. As Julia puts it, the first movie basically used the first book as a script, but this approach does not hold through the series.

The length of the seventh book as a movie … which was so long that it was divided into two parts … may have been appropriate for a number of reasons, but it is not predicted by the pattern seen earlier.

As the series went on, the movie makers seemed to regularly include numerous “cute” scenes showing things that were not central to the main plot but still made the books and movies interesting, such as Nevillle Seamus blowing himself up every time he tried something in class, or various interactions among the main characters that were not related directly to either the book’s plot or the overarching themes of the series. However, the last two movies have very little of this, and the last movie virtually none. In fact, if you look at deleted scenes from the final movie (7b) there is one such scene … when Ron and Hermione are running away from the big snake and she tells him to not say anything one might say while being chased by a big snake, but might regret saying later.

The fact, assuming that it is true, that the movies don’t simply script out the books, increasingly over the series, together with the fact that the books don’t get steadily longer (but rather, stay about the same length for a while then switch to a different length for a while) tells us something about either the books or the way the movies are made. I suspect that the contents of the books simply became thicker, even when the books themselves didn’t, and using the book as a straight forward template for a movie based on the book became increasingly difficult.

The simple idea of the books getting longer and the movies getting harder to fit into the usual time slot does not explain what we’ve been seeing. More likely, the nature of the books has changed in important ways across the series, as literary works, as well as the approach take to represent them on the silver screen.

The books:

## Comments

1. #1 Jim
December 4, 2011

It was Seamus Finnigan who kept blowing himself up.

2. #2 Greg Laden
December 4, 2011

Ah, right. I stand corrected.

Its always the Irish guy that gets blown up in movies.

3. #3 Ole Phat Stu
December 4, 2011

A sample size of seven. Congratulations.
Now do the same movie/book graph for the bible. Sample size one.

4. #4 Zeno
December 4, 2011

(The seventh book in the series was made into two books).

You mean “two movies.” (Also, the period should be inside the parentheses.)

Now, apart from petty carping, I’ll note that movies tend to be a certain length for reasons of economics, like the number of showings possible per theater per day. I’m guessing that it’s probably less flexible than book length.

While I realize that Rowling deliberately made her novels more dramatic and complex as the Potter series progressed, it also seems likely that monster success made her almost editor-proof. Who would dare pare away her golden prose down to something more manageable when she was a certified bestselling author? (Too bad, too. There was some self-indulgent sprawl in those later novels.)

5. #5 Lorax
December 4, 2011

I havent seen the last HP movie but I did find the movies basically followed the plots from the books. I do not recall any major changes. That was not the case with Percy Jackson and the Lightning Thief. The book and movie use the same characters (mostly the same way) and plot device (Zeus had his lightning blot stolen and it’s armageddon if not returned), but otherwise they are profoundly different.

6. #6 Greg Laden
December 4, 2011

Ole, that was not a sample.

Zeno, I think I see the hand of the editor in the first book or two and I noticed that this seemed to withdraw over time.

Lorax, yeah, I think the totally follow the books, and in fact, many of the people I know personally who happened to not like the movies had not read the book. Most telling of that is that these individuals found the movies hard to follow, and that is why they didn’t like them.

I think this is a notable and unusual feature of these movies; They seem to have been made with the assumption that you’ve read the books. That is something I like about the movies.

7. #7 Umlud
December 4, 2011

Now that the Twilight (bleaugh) series is wrapping up at the box office, does anyone know of similar relationships? I’m assuming that it’s similar: longer novels longer than earlier novels, movie lengths roughly the same (with the last novel also being split into two films).

What about LotR? (Or should we wait for the Hobbit to come out first?)

8. #8 Umlud
December 4, 2011

Just ran the numbers on Twilight. Can’t really do the cross comparison, though, since the second part of the last book comes out in 2012. Still, these books DO get longer over time:

Hardcover pages
498
563
629
756

That said, the softcover version of the first book was longer than the hardcover book. This was the only book that had different lengths listed, implying that there was a decision about replacing some edited-out material. It also implies that there has been an some similar amount of minimizing the editorial hand as the series took off.

9. #9 Nathan
December 4, 2011

Are all the books formatted similarly? Or do text and margin sizes and so forth change from book to book?

10. #10 Greg Laden
December 4, 2011

There are multiple versions of the Harry Potter books that probably have different page lengths, and also, most of the movies have an extended version. But these numbers would not change the overall pattern.

11. #11 Lynn Wilhelm
December 4, 2011

I happen to have my daughter (8) with me now and I showed her your post Greg. First, she has read the books and seen the movies. (I didn’t let her see the movies until she’d read the book.) She liked the movies but liked the books better.

She says: “The books had more details and were right. The movies didn’t have some of the detail from the books and the details they had didn’t match the books.”

I thought there was a lot that differed between the books and the movies. It wasn’t only the detail, but the obvious changes that were made in the movies that bugged me. As my duaghter said, “They were wrong.”

On Zeno’s comment on the shorter books in the series’ beginning. The editing and proofing could have something to do with it. Rowling did have to work hard to sell that first book and maybe she made them more simple. The books did get more complicated and harder to read after the first three. In fact the first three books are classified as Children’s books at my library, while the last four are in the Young Adult section.

12. #12 Greg Laden
December 4, 2011

I’ve noticed a great deal of variation between what people say about the contents of the books vis-a-vis the contents of the movie. I’ve read the books and seen the movies, and they are the same stories and there are a LOT of details that are reproduced, in most of the movies, right out of the books. There was not a single character added in the book, and I can’t think of any important characters left out of the movie. Almost everything in the movies happened in the same place as it happened in the book (the notable exceptions are in the very last movie during the extended attack on hogwarts act) and almost every event occurred in the same order in the book and movie except for one thing that Julia knows but that I will not say in the fifth movie, and the plots were identical.

It is also true that many book details were left out, more from the latter part of the series where the books were twice as big but the movies not. All movies do that. Most movies do that more than these.

The thing is, different people respond to different things being different.

13. #13 Ole Phat Stu
December 5, 2011

@Greg,
I assumed it was a sample because you included neither the foreign translations nor the paperback re-issues nor the large print versions for the poor of sight…

14. #14 Greg Laden
December 5, 2011

Ole, that would be an entirely different issue. I was not asking the question “how long is a Harry Potter book really?” which might involve sampling different editions or printings. Or, “given different langauges, how long would a book be and what kind of variation would there be” in which case I might have looked at different language translations. And so on.

Seriously: I was looking at the relationship between seven books, given length of book, and eight movies, given length of movies. I stipulated that any one movie or book would adequately represent the needed value since the variations were small or non existent. I used the same “version” of each, not switching back and forth between extended vs. non extended movie, for example.

Given that, there are seven, not any other number but seven, points of reference for the book length. There is no sampling. And, there are eight, and no other number other than eight, movies.

I could have remeasured the book length by looking repeatedly at the number of pages, I suppose ….

15. #15 dean
December 5, 2011

“…there are seven, not any other number but seven…”

This hints at

“Seven shall be the number thou shalt count. and the number of the counting shall be seven. Eight shalt thou not count neither count thou six, excepting that thou then proceed to seven. Nine is right out.”

Apologies to all for the, er, adjustment.

16. #16 Greg Laden
December 5, 2011

Well, did you ever wonder why there were seven to begin with?