The emotional flows of stories are important to engage the readers. Skillful writers grasp this very well by natural instinct. There are theories about this, called folkloristics. However, is there a way to see the flows in a graph? Linear algebra and natural language processing (NLP) kick in.
Andrew Reagan at the Computational Story Lab, University of Vermont, together with his colleagues and collaborators, did a numerical studies about this. [Reagan et. al., 2016] Their paper is now on the arXiv. He prepared a set of words with scores that quantitatively describe their sentiments, as in sentiment analysis. He then went through the text with a sliding window to measure the sentiments. Then for each book, there is a vector of a time series of these sentiment scores. For example, using this method, the plot of the emotional scores, or the emotional arc, of J. K. Rowling’s Harry Potter and the Deathly Hallows is as shown in the following plot: [Reagan et. al., 2016]
They did the same thing with other English fictions in the Project Gutenberg Corpus, giving a vector of these emotional scores for each fiction. They performed a principal component analysis (PCA) for all these books (represented by a matrix containing all vectors). PCA is a common dimensionality reduction techniques, and also useful for information retrieval (IR) in another name called latent semantic analysis (LSA). Reagan and his colleagues identify six major components of these emotional arcs, as shown below: [Reagan et. al., 2016]
These computational studies on fictions further reinforce our common belief that (good-selling) fictions do have resonating themes to keep the readers.
- A. J. Reagan, L. Mtchell, D. Kiley, C. M. Danforth, and P. S. Dodds, “The emotional arcs of stories are dominated by six basic shapes,” arXiv:1606.07772 (2016).
- “Data Mining Reveals the Six Basic Emotional Arcs of Storytelling”, MIT Tech Review (July 6, 2016). [link]
(Feature Image: a scene from the movie adapted from C. S. Lewis’ The Chronicles of Narnia: The Lion, the Witch and the Wardrobe)