A dictionary is a kind of text. It's a specific kind of text, but it is text nonetheless: print dictionaries are mostly made of words, and these words as they appear on paper are ususally differently styled from each other. The main word in the entry -- lemma -- is usually bold, whereas examples, for instance, can be set apart from the rest of the text by cursive. Different dictionaries use different presentational styles to make it easier for their readers to find and extract particular bits of information that they are looking for. But despite the variety of styles used, all dictionaries share a hierarchical model of organizing information.

In the late 1980s and into the 1990s a group of scholars including Allen Renear, Elli Mylonas, and David Durand developed a theory for the practice of text encoding specifically, and text more generally.  It was called an ‘Ordered Hierarchy of Content Objects’ (OHCO).

They proposed that although different kinds of texts may be organized differently, they all still have a hierarchical organization. In their first iteration of the OCHO model, they asserted

Within the lowest level subsections are objects like paragraphs, sentences, prose quotations, verse quotations, equations, proofs, theorems, and so on. Many of these objects can be decomposed further. This structure is hierarchical because these objects “nest” inside one another like Chinese boxes. It is ordered because there is a linear relationship to objects – for any two objects within a book one object comes before the other. (Renear)

Whether we draw our source of inspiration from Russian matryoshkas or Chinese boxes, we all know how structural 'nesting' works in books: a book may consist of chapters, a chapter may consist of sections, each section may contain a separate title and several paragraphs. Inside paragraphs we may find, for instance, lists etc. These content objects fit neatly into one another, from the smallest (a letter or a word) to the largest (a book or monograph), with a myriad of other nested units in between (sentences, paragraphs etc).

While this theory was instrumental for conceptualizing the practice of text encoding, it never fully accounted for the problem of overlapping hierarchies. Overlapping hierarchies break the neatly nesting pattern described above. For example, a metaphor in a poem may cut across two or more lines. The creators of the OHCO theory concede that this may be more than a technical issue and that it may point to some of the thorniest issues surrounding text encoding as an intellectual endeavor.

Textual editors such as Jerome McGann, D.F. McKenzie and Peter Schillingsburg had been developing different understandings of text. They found the OHCO model was too simplistic a model to represent complex works, particularly literary. Essentially they argued that texts can have multiple structures and diverse meanings, some outside the text itself. Narrative events may span many paragraphs and indeed may overlap. Verse drama contains dialogue lines (speeches), metrical lines, and sentences. But these sentences and metrical lines overlap in the case of enjambment or when a character begins talking and another interrupts. All these hierarchies have equal claim to representation.

When it comes to dictionaries, however, we're actually quite lucky. Not only because dictionaries, among a certain group of individuals, make great bedtime reading material, but because dictionaries are prime examples of structured data.

Dictionary entries are, by conventions of the genre, already hierarchical. If you think of a prototypical dictionary entry as a box, you will realize that it's a box containing several smaller boxes: a lemma, grammatical information and a 'senses box'. A sense box contains one or more individual senses. Inside each sense, we may find a definition and an example.

Unlike some of our colleagues who are eternally damned to ponder the overlapping hierarchies in poetry, for instance, dictionary encoders will most likely never encounter this problem. Lexicographers like to create order out of chaos. If you find an example of overlapping hierarchies in a dictionary, do let us know! We like a challenge.

Further Reading

Hockey, Susan, Alan Renear, Jerome McGann. 'Panel: What is text? A Debate on the Philosophical and Epistemological Nature of Text in the Light of Humanities Computing Research. Web. 29 August 2016.

McGann, Jerome. Radiant Textuality: Literature After the World Wide Web. London: Palgrave, 2001.

Renear, Allen, Elli Mylonas, and David Durand. “Refining Our Notion of What Text Really Is: The Problem of Overlapping Hierarchies.” N.p., 6 Jan. 1993. Web. 17 Sept. 2012.

Scholen, David and Sandra Scholen. 'Beyond Gutenberg: Transcending the Document Paradigm in Digital Humanities'. Digital Humanities Quarterly. Vol. 8 No. 4. 2014.

Shillingsburg, Peter L. Scholarly Editing in the Computer Age: Theory and Practice. Ann Arbor: University of Michigan Press, 1996.