# A Hierarchical Orthographic Similarity Measure for Interconnected Texts Represented by Graphs
## 4 Representing a Textual Corpus as a Graph
### Graph Representation of a Textual Corpus
Then, we discuss the graph-based text representation of this corpus and the methods used in the experiments in Section 6.2. In Section 6.3, we describe the setup of the experiments alongside the methods employed for evaluating the proposed similarity measure. Next, we list and discus the results of our experiments in Section 6.4. Lastly, in Section 6.5, we provide an illustrative example, where we show the interactive capabilities of the proposed graph model implemented in a graph database. Figure 5: Subset of the graph-based text representation for the texts in Example 1 after computing the similarities between all elements. Word nodes are indicated in green and display their text property, while Sentence nodes are indicated in yellow, and Text nodes, including their numeric id property, are indicated in blue. The values of the rank property are shown on the directed edges (grey) between different levels of the graph, and the similarity values are indicated on the undirected edges (black) between the same level text elements. To avoid clouding the image, only the relevant similarity relationships are displayed. ### Dataset: Byzantine Book Epigrams

Byzantine book epigrams are poems nestled in the margins of medieval Greek manuscripts. They are typically short and tell the reader more about, for instance, the manuscript's content, the individuals involved in its production or even the emotions experienced by the scribe upon completing the manuscript. These epigrams are typically known to be orthographically inconsistent texts with a complex tradition. That is a tradition, or in other words the transmission of the texts throughout history, in which texts were split-up, (re)combined or elseways reworked during their copying process. As a result of this complex tradition, where combinations of words and (half)verses are often re-used throughout a variety of epigrams, the corpus of Byzantine book epigrams displays an expansive amount of interconnections among its texts [41; 50]. The orthographic irregularities displayed in these book epigrams arise not solely from factors like spelling and transcription errors, unstandardised punctuation, and text wrapping. They are also caused by the evolution of the Greek language. Particularly noteworthy is the phonetic evolution known as _itacism_. _Iacism_ denotes the shift of the classical pronunciation of the vowels \(\iota,\eta,\iota,\eta\) and the diphthongs \(\varepsilon,\omega\) converging towards the pronunciation of \(i\). This results in a corpus where all the aforementioned vowels and diphthongs are used interchangeably [41; 50; 51]. The complex and interconnected nature of these Byzantine book epigrams makes them an ideal corpus for evaluating the capabilities of the proposed similarity measure. The Database of Byzantine Book Epigrams (DBBE) ([[https://dbbe.ugent.be](https://dbbe.ugent.be)]([https://dbbe.ugent.be](https://dbbe.ugent.be)), accessed on 1 February 2024) [50; 52] is composed of experts and contains an extensive collection of Byzantine book epigrams, complemented by manually composed groups of similar texts. These groups of similar texts within the DBBE serve as a ground truth for evaluating the proposed similarity measure. Two categories of such groups exist in the DBBE: those comprising similar epigrams and those composing similar verses. Since these groups are manually composed by experts, they include texts that are only partially known or variants of a text where synonyms are used. For the experiments, a representative subset for each category of these groups is carefully identified by experts and exported from the DBBE dataset. The subset of verses is composed of the verses contained in the verse groups with identifiers 15681, 15470, 14667, 11233, 14852, 12251, 15904, 14932, 14802, 10671, 4634, 15377, 12290, 14866, 15278, 12121, 13035, 15327, 6342, 5549, 445, 2520, 3949, 5354, 5840, 6353, 9033, 10869, 12122, 15261, 15652 and 14872, resulting in a subset of 750 verses to be compared.