Mapping Metaphor: Visualizing the History of Modern English

I love words, as anyone who meets me tends to figure out pretty quickly.  So the University of Glasgow’s visualization of the semantic connections between different meaning categories in the English language, “Mapping Metaphor”, was definitely interesting to explore.

The home page greets you with a large, memorizing ball of string.

Mapping Metaphor Home

The first thing you see when you visit the “Mapping Metaphor” site.

Thankfully, near the top of the page is a line of links, one of which is “How to use”.  A user very quickly learns to rely on the little green box that lives on the left side of every page in the site, which in the case of this page, lets you select between a text explanation or a video walk-through, in addition to links to the FAQ and various other helpful pages.  The text walk-through is thorough, if a bit cumbersome to read.  The video walk-throughs, however, have a distinct shortcoming: they are video only.  They lack any audio to accompany the highlighted cursor floating around the screen.  Without either reading or watching, though, the green ball of grey string is just something that lights up when you click it, and brings up boxes with information that is little better than literal code to the casual observer.

That being said, after a little reading and some trial and error, the visualization engine appears to be a fairly robust machine.  The primary data set from which it draws its information is the Historical Thesaurus of English [1], which in turn draws the majority of its data from the Oxford English Dictionary and A Thesaurus of Old English [2].  The Historical Thesaurus, and the visualization in turn, rely on the division of all words in English into semantic categories.  “Mapping Metaphor” uses both color and alphanumerical designations: color indicates the three umbrella categories—The External World, The Mental World, and The Social World—and then a number-letter-number code indicates all subcategories, with color used to further differentiate between selected categories.  All categories are based on the Historical Thesaurus [3].

Drawing and demonstrating the connections between words in these categories, though, is the point of “Mapping Metaphor”.  And that, according the the creators, was entirely a manual process.  With the Historical Thesaurus as a starting point, all the contents of each category were cross-referenced against the contents of all the other categories; and wherever a word match was found, that word was marked for analysis [4].  All the word matches were compared with lexical data about the historical use of the word, and any changes therein.  Words with purely metaphorical connections, rather than homonymy or other semantic links, were then separated out [5].  It is those particular words—over ten thousand of them, in the end—that were then mapped in the visualization.  The map differentiates between “strong” and “weak” connections, or categories with many metaphorical connections versus those with only a few [6].  According to the creators, all decisions about how words were classified and whether connections could be verified were reviewed multiple times, and reviewers constantly referred back to the original sources.

The data is maintained in an SQL database and visualized using a JavaScript library called D3 [7] [8].  Because D3 focuses exclusively on web languages like HTML for its coding, the visualizations of “Mapping Metaphor” will work on almost every modern computer.  The trick with understanding the visualizations is that they require a decent functional knowledge of the vocabulary of language analysis and some idea of how the English language developed.  Without that background, the visualization is just a ball covered in grey lines surrounded by words.  Very little of the information would make sense to a casual user, even after reading the directions.  However, to someone with a bit of experience, “Mapping Metaphor” contains a host of information.

Completed metaphor card

What the creators are still working on, however, is one of the more practical uses of the visualization: every acknowledged connection has a “metaphor card” listing the number of words in common between the categories, but lacks examples or a time period in which the connection was first made.

Blank metaphor card





According to the FAQ, the process of linking the “metaphor cards” with its source information in the Historical Thesaurus and the Oxford English Dictionary was not originally conceived as part of the project and, although efforts are ongoing, that aspect of the site has not yet been completed [9].

As a whole, the software underlying “Mapping Metaphor” is robust, open source, and designed for web-based viewing, which makes the visualizations easy to play around with.  However, as with many such scholarly projects, a viewer with no frame of reference for the data they are looking at would be easily frustrated.  Unlike “Six Degrees of Francis Bacon”, which immediately greets users with a how-to video, “Mapping Metaphor” relies on a committed, knowledgeable user in order to function as intended: as a visualization of the connections between words in the English language, and a demonstration of the constant evolution of meaning.


  1. “About the Project.” Accessed January 23, 2017.
  2. “About the Thesaurus.” The Historical Thesaurus of English. Accessed January 24, 2017.
  3. “About the Project: Method.”  Accessed January 23, 2017.
  4. Ibid.
  5. Ibid.
  6. Ibid.  The example provided was that between the category Weather and the category Anger, which had a very strong connection.
  7. “How to use: FAQs.” Accessed January 23, 2017.
  8. D3 is an open-source JavaScript library based on web standards:
  9. “How to use: FAQs.” Accessed January 24, 2017.  However, the Historical Thesaurus is available to the public, and most universities (including IUPUI) have access to the Oxford English Dictionary via online subscription.

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