Do Longer Chapters Mean More Hits?
Thanks to several users on Discord for this question, especially Anonymous Lawyer who inspired the question by asking “Who writes the longest fics?”
This is a relatively simple question without a simple answer. To answer it, I plotted the average chapter length versus the hits per chapter. This helped control for multi-chapter stories, which by their very nature tend to get more hits. as readers click on the story to keep reading.
Since we’ve previously shown that readership is statistically independent of a work’s rating, I decided to control for work completion and got some surprising results.
So there is a return on investment for chapter length and hits it looks like, where fics with longer chapters gradually see less hits than fics with shorter chapters. Likewise, there’s a clear trend for fics that are incomplete -- the boundary is lower.
One of the things I love about doing DataFan is I’m actually running into and solving some very unique real world data science challenges, such as how to handle data where there seems to be a clear threshold. That is, we can say that the following generally holds true for the trend:
Hits per chapter is less than or equal to some function of words per chapter.
So what we see is that while there’s some sort of relationship between chapter length and the hits per chapter, there are also other variables clearly in play. If Hit Count could be considered solely dependent on Chapter Length, then we’d see a clear regression curve.
What about number of chapter a fic has? Does that have an impact?
There’s two ways to tell this. The first is to create a bubble plot, where the size of the bubble approximates the number of chapters a fic has. Again, the color represents whether a fic is complete or not.
That’s... really not helpful except to show that incomplete works tend to have more chapters.
Okay, so the other way we can visualize the data is to make it 3 dimensional. For that, I added a third dimension -- number of chapters posted -- to the graph. Unfortunately, 3 dimensional data is not easy to display statically, but you can interact with it if you download the notebook. However, I’ve got a gif below of the data.
Again, there’s no clear relationship between chapter length, hits per chapter, and the number of chapters posted. In the gif above, the green points are incomplete works and the blue points are complete works.
So next I did a technique called dimensionality reduction and reduced the size of my dataset to contain only completed one-shots. That is, I removed all works that were incomplete and had more than one chapter, leaving me with a sample size of about 150,000 works still.
Again, we see that there’s a clear threshold for when chapter lengths don’t seem to generate hit counts, but again it’s not single variable.
It would be disingenuous to say that hit counts are independent of chapter length, but it’s also not true to say that writing short chapters gets you more hits. The data just doesn’t support that.
Rather, other factors contribute to the hit count of a work. So what are those other factors? Well... one thing we can do is calculate correlation. Correlation does not equal causation, as hilarious charts like the one below show:
Usually, you need some domain expertise to decide when a correlation is related to causation. That’s why data scientists are not JUST statisticians and programmers, but also people who have interdisciplinary understanding of the subject matter. If you’re reading this tumblr, chances are YOU are a domain expert in fanfiction, or at least enough of one to help discern correlation and causation from each other.
The graphic above shows the data for one column of the correlation matrix, which helps visualize how different data is correlated to each other. For reference, here is the correlation plot of a limited segment of the data:
Areas that are red show high positive correlation while areas that are blue show high negative correlations. In other words, there’s a positive correlation between the number of chapters posted and the fic’s word count. For our purposes, we want to only look at the first row of the correlation plot -- the hits.
To determine whether something is correlated, and by how much, we need to define a threshold. We’ll pick a threshold of +/- 0.01. So from our list, which data points do we keep? (ID and Work ID are the same thing -- they’re the unique identifier I use for each work)
Completion, ID, Work ID, Gen, F/M, Num Authors, Num Fandoms, Multi, M/M, Average Chapter Length, Num Freeforms, Posted Chapters, Words, Bookmarks and Bookmarks/chapter, Kudos and Kudos per Chapters, Comments and Comments per chapter, Hits per chapter.
As domain experts on AO3, the next step is to determine which of those metrics that have a high correlation are actually causation metrics. For example, Hits per chapter is a correlation, but it’s not the cause of higher hit counts. Same with Kudos, Bookmarks, and Comments, which are not factors an author has direct control over.
At first glance, it might be tempting to throw out the ID/Work ID (which are the same thing) but actually the ID can be useful. I use the same IDs that AO3 assigns to a work when it’s posted, meaning that LOWER ID numbers are works that have been on the archive much longer than works with HIGHER ID numbers. So we’ll keep that.
Gen, F/M, Multi, M/M, and F/F are pairing designators. High correlations mean that pairing designators have an effect on hit count, while low correlations mean there is little affect on hit count. We removed F/F as an indicator because it had a low correlation, meaning that people click on a fic whether or not it’s got WLW in it.
On the other hand, people were less likely to click on a fic if it had Gen (no pairings) or F/M pairings in it. M/M fics on the other hand have the highest positive correlation at almost 10x our threshold of significance, meaning it looks like people really do like their M/M.
Average Chapter Length and overall word counts were also significantly correlated with the number of hits. This goes back to what was shown earlier: there is a relationship, but it’s not single factor.
So to answer the question: The average length of your chapter is one of many factors that contribute to your hit count. The others include: completion status, how long ago you posted, pairing types, total word count, and how many chapters you have posted.