So far, we’ve looked at using word clouds and character rankings, and document similarity, but there are a few more NLP tools left to use in our analysis of The Wheel Of Time series. Today, we’ll look the results of learning word associations. To do so, we’ll need to use a modification of the document vectors discussed last post to uncover some very interesting relationships between the words in our corpus.
There are roughly 50,000 unique words used in the series. Whereas before we needed a 14 x 50,000 matrix for the book similarity, we are going to need a 50,000 x 50,000 matrix to compare our words. For books, it was easy to know which words were part of the book. It is harder to see how a word can be related to other words.
The trick commonly used to create the word vectors is to use machine learning algorithms to predict the local context of a word. There are a few variants, but they are all known as Word2Vec. As a simple example, if we are trying to find words similar to weave, we could find each instance of this word in the series. Then, by aggregating over the 5 words before and 5 words, we can calculate frequencies of these neighboring words as the values in our vector. We can further refine this by giving more weight to closer words. Finally, some machine learning and data compression is added to make all of this computationally feasible. A really fun online tool to explore the Word2Vec concept is Word2Viz, with graphical visualizations for many genre and topics.
In particular, I will be using the Gensim Python implementation of Word2Vec, which can learn a new relationship matrix for any supplied corpus of text, and provides some useful functions to make it easy to query the matrix once constructed.
Discussions of plot points and threads across the whole series follow. Please take appropriate cautions if this is important to you.
When we use these learned vectors for each word, we can ask about the similarity between two words. These are words that commonly show up in the same contexts throughout the corpus. In the table below, each row includes a key word and the five closest words according to the Word2Vec algorithm.
Since this series is an epic battle between good and evil involving magic, we can find some interesting connections between these light and dark words. Reality is often described as the pattern, and ta’veren are individuals spun out to fix the pattern when things go wrong. Magic flows from the One Power, and is wielded by creating a weave.
Next, we can see how common English words can pick up new shades of meaning from context within the series. Rand’s sword brings out common (and uncommon) weapons, characters most often use coins for food and drink, Mat’s constant rattling dice are related to other card and board games, Mat’s bond with the horn is related to the fateful dagger, Perrin’s wolf aspect evokes both his arch-enemy and his wolf mentor, and we have empirical evidence that Nynaeve’s braid gets a tug.
Finally, we can also see associations made between location words in the texts, for both countries such as Andor, towns/cities like Emond’s Field, and even the dream world of Tel’aran’rhiod. I’ve included another table of many more words below, but there’s more to uncover first.
Since we have turned each word into a vector, which is a mathematical object, we can actually do simple math operations on these words. Instead of 1 + 2 = 3, what happens when we say KING - MAN + WOMAN? This kind of word math is reminiscent of the analogies found on old SAT exams, and might make more sense when written “MAN is to KING as WOMAN is to QUEEN”.
If we use The Wheel of Time as our corpus, can we computationally understand some of the plot connections and relationships? Let’s test it out. Here are a few analogies, written using abbreviated notation, that might make sense if you have read the series.
- EGWENE : SAIDAR :: RAND : ??
- AIEL : WISE :: FOLK : ??
- MAT : TUON :: PERRIN : ??
Once you think you know the answers, scroll ahead to see what the algorithm found!
Here we go!
EGWENE : SAIDAR :: RAND : SAIDIN
Good work, Word2Vec! There are two halves of the One Power: one male called Saidin, and one female called Saidar. The algorithm finds enough context to when Egwene and Rand use their powers to distinguish these two halves.
It can also pick up on titles and subordinates for these characters, and learned the following correct analogies:
EGWENE : AMYRLIN :: RAND : DRAGON
EGWENE : SISTERS :: RAND : ASHAMAN
AIEL : WISE :: FOLK : WINDFINDER
The algorithm is also capable of learning key words for the same thing across different cultures. While Aes Sedai is the name given to female channelers, some of the outlying communities and cultures use different variants. In the Aiel, channelers and known as Wise Ones, while in the Sea Folk, the Windfinders use their powers influence the weather. Here are a few more using the Aiel as a base reference:
AIEL : WISE :: SEANCHAN : DAMANE
AIEL : CARACARN :: FOLK : CORAMOOR
AIEL : SHAIDO :: TOWER : REBELS
For the Seanchan, channelers are collared and enslaved, earning the name Damane. The Aiel prophecies tell of the Dragon Reborn as Caracarn, while the Sea Folk name him Coramoor. Finally, one of the Aiel tribes goes rogue and fights the others, making them an interesting analogy to the band of Aes Sedai rebelling against the White Tower.
MAT : TUON :: PERRIN : BERELAIN
Finally, we see some of the character relationships can also be understood, although maybe not as we might expect! Mat and Tuon have a very tumultuous love/hate relationship, and our algorithm perceives it to be closest to Perrin’s one-sided relationship with Berelain. His wife Faile would not be happy about that! The second-closest word analogy was Galad, which also follows the troubled-then-reconciled relationship arc, and finally coming in third was Faile.
Here are a few more with Mat as the base reference
MAT : TUON :: RAND : AVIENDHA
MAT : DICE :: PERRIN : HAMMER
MAT : GHOLAM :: PERRIN : SLAYER
When paired with Rand, we again see the love/hate relationship arc appear, choosing Aviendha as the closest fit.
Character traits can also be learned, with Mat’s penchant for dice and gambling being analogous to Perrin’s hammer, used for blacksmith work and other tasks.
For the third, we are trying to find the villan for each character. Mat must spend time fighting the Gholam across a few books, while Perrin battles with the Slayer in the dream world Tel’aran’rhiod. Finally, when paired with Rand instead, Word2Vec learned his enemy was Demandred, while Egwene’s nemesis was Moghedien.
These pieces only scratch the surface of what is possible to find in the Word2Vec data. One thing to note, because this is a probabilistic algorithm, different iterations will produce similar but slightly different results, this is not the only possible set of vectors that can be learned from this corpus.
What other analogies or associations interest you? I’ll leave with some of the character associations it learned, which pair well with what we saw in our character rankings analysis.