Putting L ow G erman on the Map (of L inguistic L inked O pen D ata) (2025)

Abstract: We describe the creation of a cross-dialectal lexical resource for Low German, a regional language spoken primarily in Germany and the Netherlands, based on the application of Linguistic Linked Open Data (LLOD) technologies. We argue that this approach is particularly well-suited for a language without a written standard, but with multiple, incompatible orthographies and considerable internal variation in phonology, spelling and grammar. A major hurdle in the preservation and documentation of and in the creation of educational materials (such as texts and dictionaries) for this variety is its internal degree of linguistic and orthographic variation, intensified by mutually exclusive influences from different national languages and their respective orthographies. We thus aim to provide a “digital Rosetta stone” to unify lexical materials from different dialects through linking dictionaries and mapping corresponding words without the need for a standardvariety. This involves two components, a mapping between different orthographies and phonological systems, and a technology for linking regional dictionaries maintained by different hosts and developed by or for different communities of speakers.

## background while discussing the 'digital fitness' of languages @xcite with respect to their usage, dissemination and accessibility of web resources for speakers of that languages, emphasis is often put on speaker community size and the number (or existence) of resources and tools. however, such measures can be too narrow since tools like spell checkers, chatbots, mt technology, dictionaries, or plain texts may not be equally helpful to all speakers due to the language's degree of internal diversity, varying orthographies, and accepted standards. as a point in case, we describe an approach for creating both a machine-readable dictionary and interdialectal links for low german (low saxon, iso 639-2 nds), a european minority language with considerable phonological, morphological and orthographic diversity. although modern low german has developed vibrant (regional) literature since about 1800, it lacks a written standard, corpora, machinereadable and interdialectal dictionaries, and, in particular, parallel texts and texts attested in more than one variety of low german, limiting modern nlp applications. likewise, off-the-shelf embeddings or llms are impractical due to inconsistent web training data. 1 without enforcing normalization and standardization, effective nlp support for low german requires a digital rosetta stone that allows us to integrate diverse language varieties uniformly. although language normalization is possible, it has been a controversial topic @xcite , and -beyond the level of geographically confined regions -seems to be largely rejected by the speaker community. instead, we focus on creating 'non-invasive' synergies between dialect-specific resources by linking regional dictionaries and providing a mapping routine capable of spotting formally corresponding words across dialects. in this paper, we primarily focus on methods to access such data for both humans and machines. while web-scale linking of dispersed data sources can be addressed using rdf and linked open data technology @xcite , providing our data as linguistic linked open data (llod) involves a number of challenges in data modeling (of the dictionaries and inter-dictionary links), accessibility (i.e., readability for a human), and legal constraints (since many online dictionaries use pro-prietary licenses that restrict direct use, but linking is permitted). low german or low saxon (self-designation plattdüütsch, nedersassisch or nedersaksisch ) is a west germanic language historically spoken in northern germany, the netherlands and the southern coast of the baltic sea. closely related to dutch, high german and frisian, it has followed its own developmental trajectory since its first recorded texts from the 9th c. ce @xcite and is protected under the european charter for regional or minority languages (ecrml). historically, (middle) low german served as a lingua franca around the baltic sea. however, with high german (in germany) and dutch (in the netherlands) replacing it as the dominant languages of education, administration, and media since the 17th c., it is now considered threatened (vulnerable) @xcite . while it still has millions of passive speakers, active speakers are far fewer and to a large extent elderly citizens @xcite , making intergenerational transmission a key challenge. this demands both educational material and digital tools, yet basic nlp tools such as spell checkers, machine translation, speech recognition, and text-to-speech systems are effectively absent. the fragmentation of modern low german dialects -which have diverged greatly since the middle ages (tab. 1) -further complicates digital communication. for example, some northern dialects lost the unvoiced vowels of middle low german (and thus parts of their morphological inventory), while others preserved them. alongside this north-south division, there also exists an westeast division that reflects the expansion of low german towards formerly slavic territories during the middle ages, with western dialects (historically) using a uniform verbal plural in -(e)t, and eastern dialects (historically) using a verbal plural in -en. dialects east of the oder ceased after wwii but gave rise to emigrant varieties like pomerano (a regionally recognized minority language in brazil) and plautdietsch (spoken by the mennonite diaspora, predominantly in the americas). this fragmentation makes it difficult to use the language in digital communication -reducing its visibility and usability in the modern world -and to develop tools for its low german speakers and learners. the absence of nlp tools also hinders academic research, automated language processing, and digital content creation. despite these challenges, low german enjoys cultural and regional recognition. efforts to revitalize the language include educational programs, literature, radio broadcasts, and online initiatives. these resources may play a role in transmission and revitalization of the low german language, and indeed, this is what we see for other minority languages all over the world. however, to preserve low german, more work is needed to integrate it into digital spaces. developing nlp tools, expanding online resources, and boosting media presence are crucial for its survival as a living language. currently, fundamental nlp resources are lacking, including corpora @xcite , parallel corpora, and machine-readable dictionaries. a machine-readable dictionary (mrd) is a lexical resource structured for computational use rather than human readability. unlike traditional dictionaries, mrds are formatted in a way that allows software applications to process and analyze linguistic data efficiently. they store information such as word meanings, grammatical properties, pronunciations, and translations in a structured manner to facilitate the development of downstream applications. for low-resource languages, mrds play a crucial role in developing foundational nlp technologies. in particular, this is the case for language varieties that have been the subject of linguistic research in the past (so that word lists or dictionaries are available), but that have been largely neglected by nlp or corpus linguistics (so that no digital corpus data is available). we are unaware of any existing comprehensive low german mrd, aside from isolated low german terms in foreign-language editions of dbnary @xcite (which is crowd-sourced and inconsistent). this paper describes the development of a prototypical interdialectal mrd for low german, consisting of two parts, a core built from a north low saxon dictionary of dithmarschen @xcite , republished in 2019 as frie' woor 'freeware' digital-born docx and pdf files. to the best of our knowledge, this is the only digital dictionary of a regional variety of low german in germany for which free redistribution is explicitly allowed. 2 this is complemented by interdialectal links, derived from various digital dictionaries, though all are designed for human consumption, and not for subsequent use in natural language processing. in addition, most of these are copyright- a key technology for building structured and interoperable mrds is ontolex-lemon, an rdf vocabulary designed for representing lexical and semantic data on the web @xcite . ontolex allows lexicons to be linked to external knowledge bases and other linguistic resources, enhancing interoperability. it uses the resource description framework @xcite , a w3c standard to provide a flexible, graph-based data model that enables rich semantic annotations and structured linguistic relationships. together, these technologies ensure that dictionaries for lowresource languages are not isolated but can be integrated into broader linguistic ecosystems, facilitating cross-linguistic research and nlp. by leveraging ontolex and rdf, mrds for low-resource languages can be built in a way that supports automated processing, encourages digital preservation, and enables their incorporation into modern nlp applications. these technologies make it easier to link lexical resources across languages, ensuring that low-resource languages gain better representation in computational linguistics and digital tools. as such, ontolex has been a cornerstone for integrating lexical data into the linguistic linked open data cloud @xcite . the linguistic linked open data (llod) cloud @xcite @xcite ) is an interlinked network of linguistic resources following linked data principles @xcite . it provides a semantic web-based infrastructure for representing and integrating linguistic data, including lexicons, corpora, terminologies, and ontologies. 3 a key advantage of the llod approach is its ability to connect diverse linguistic datasets, making them accessible for computational use. the llod cloud benefits low-resource languages by linking their limited linguistic data to richer datasets, fostering nlp development and linguistic research. by structuring linguistic resources using open standards, the llod cloud contributes to the creation of multilingual and interoperable nlp systems, supporting tasks such as machine translation, semantic search, and corpus analysis. for languages with scarce and scattered data, llod is vital for digital preservation and computational access to linguistic knowledge. ## linking the wöwö a number of online dictionaries for low german are available, but usually not under permissive licenses. as a result, we focus on the wöwö dictionary as our primary dataset, and do currently not provide linked data editions of other low german dictionaries. however, these are accessible online, usually with uris identifying the respective lemma, and we use only this information (the existence of a lemma and the assignment of a particular url) to create a machine-readable 'entry point' (i.e., an index) in rdf. as we do not use any specific information from the dictionaries other than the existence of a lemma, we assume that this information does not meet the threshold of originality legally required for copyright to apply @xcite , so that these lod indices to other low german dictionaries can be published as addenda to the wöwö dataset regardless of the licensing situation of the full data sets. however, should these respective resources be ever served as linked data or be made accessible under a more permissive license, the information from the indices/links we provide can be seamlessly integrated into the respective dictionaries. ## querying interdialectal links for evaluation, we used a single sparql select query to retrieve all wöwö lemma forms, their reuter wwb match 0.66 (33/50) 0.59 (29/50) approx. match 0.16 (8/50) 0.06 (3/50) mismatch 0.18 (9/50) 0.36 (18/50) with this query, this information can be conveniently retrieved and exported to html. both the query and its results are bundled with the release of our data and a snippet of the html output is shown in fig. 5 . note that this uses the urls of the lexical entries (i.e., for external dictionaries, their native url) as the basis for hyperlinks, so that all links can be interactively explored. on this basis, we conducted a qualitative evaluation for 50 randomly sampled links for reuter and wwb (tab. 2): overall, we found the majority of links (82% for reuter, 65% for wwb) to represent exact or approximative matches, and in line with relative proximity of reuter and wöwö varieties, with much better results for reuter. one major factor for the high number of mismatches is that both north low saxon (wöwö) and mecklenburgian (reuter) drop unstressed middle low german e (apocope and syncope), whereas the westphalian varieties (wwb and twents) normally maintain it. as we cannot reliably distinguish stressed and unstressed syllables, the westphalian (wwb and twents) normalization allows to omit any e, so that words like twents efn 'respectable' and ven 'swampy meadow' include the same (possible) normalizations and can thus be easily confused. we use levenshtein distance as an additional disambiguating factor along with normalization-based confidence, and dialects with apocope and syncope are likely to yield forms that are more similar to wöwö, whereas the degree of variation (and the levenshtein distance) is generally greater to dialects without apocope. by approximative matches, we mean that either one of the words in a multi-word expression is identical, e.g., block speck 'chunk of bacon' with plattmakers block 'block, chunk, large piece', or that it involves a more or less transparent shift of meaning, e.g., ool 'eal' with twents oal (derogative nickname for persons notorious for speaking glibly), based on twents oal 'eal' (which is also the total number of links predicted for individual dictionaries is summarized in tab. 3, reporting only the most confident link for every source dictionary lemma. in total, the linking covers 8,001 wöwö entries, thus conforming these to be lemma forms. this number appears to be small in comparison to the 26,713 lexical entries of wöwö in total, but to a large extent, this is due to compounds and derived forms that were included in wöwö, but not (or, at least, not as independent lemmas) in the other dictionaries. as such, we have 41 lexical entries for trecken 'to pull' and its derived forms in wöwö, but only 18 of these have been linked. the reason is not so much that words such as rantrecken 'to pull here', rintrecken 'to pull inside', roptrecken 'to pull up there', rövertrecken 'to pull over', rumtrecken 'to pull over', or ruuttrecken 'to pull out' don't exist in the other varieties, but they haven't necessarily been included in the other dictionaries because their formation follows a regular and productive morphological pattern and they don't convey a semantic meaning that cannot be deduced from its parts. in fact, any locative adverb can be combined with trecken and similar verbs of motion. the same holds true for nominal compounds, which are about as productive as in high german, but are normally not included in the other dictionaries unless they have special semantics that cannot be derived from its parts. ## discussion and outlook we propose a method for creating a cross-dialectal lexical resource for low german using llod technologies. this approach is particularly suited to a language that lacks a standardized written form, exhibits multiple conflicting orthographies, and shows significant internal variation in phonology, spelling, and grammar. we provide a conversion of the wöwö dictionary of the dithmarschen dialect of north low saxon into rdf and use this as a lexical backbone. in a second processing step, this was enriched with cross-dialectal links based on formal agreement of wöwö lemmas with lexical entries from dictionaries of 5 other low german dialects. this data is provided as rdf data, with three files representing the original wöwö and one rdf file per external dictionaries. these rdf files define lexical entries and their respective canonical forms, but they do not provide additional details beyond the location of the corresponding lexical entry on the web -the uri of the lexical entry is the url of the underlying lemma. with the exter-nal dictionaries not providing an rdf view on their content, this is not actually linked data, as these uris do not resolve to machine-readable data, but it is possible to query the graph and to provide a tabular export that not only includes (excerpts of) wöwö information, but also links with external dictionaries. we provide an html view on this tabular export, and for a human, this html file (resp., for a machine, the underlying rdf data) is actually capable of serving as a "digital rosetta stone", linking dictionaries and mapping corresponding words across dialects -without resorting to a standard variety or spelling (which, for the case of low german, does not exist). aside from supporting speakers and learners in their exploration of interdialectal differences and similarities, this approach also enables new applications in the technical realm: since there are no cross-dialectal parallel texts for low german, linking dictionaries could facilitate the induction of multidialectal word embeddings -and, building upon that, multidialectal contextualized embeddings. each of the dialects examined here has its own literary tradition, written in different orthographies. while our linking method primarily serves to establish a baseline for future research, our crossdialectal dictionary provides a testbed for a number of community standards for machine-readable dictionaries on the web in general, and for nonstandardized, low-resource languages in particular. we observed a number of potential gaps in the existing ontolex vocabularies. 1. as our interdialectal links are created by heuristic means, we would like to be able to express to what extend a user can rely on the information conveyed by a link. this includes candidate links (with a property such as '...:possiblematch'), but also the possibility to mark links as (un)verified hypotheses. it should be noted that confidence scores are a recurring component of lexical resources, but apparently, no standard practice has been established in that regard. more generally, this is an intensely researched problem in the rdf world, and one of the key motivations behind rdf-star (rupp et al., 2024). 12 3. lexinfo currently does not support the reification of lexinfo:geographicalvariant (and its sibling properties). as we have to point with lexinfo:category to an object property, we move the entire dataset out of the realm of owl2/dl and into owl2/full. as a result, standard reasoning techniques cannot be applied to the resulting lexical knowledge graph. it would be ideal, if there would be an individual with a similar meaning. in addition to this, we found some solutions for apparent ontolex gaps, and these may even entail future simplifications: as such, there is an apparent gap of a counterpart of translation sets for relations other than translations in ontolex-vartrans, but we found an acceptable work-around in dct:dataset, and we would suggest this as a best practice for other types of lexical-semantic relations, as well. yet, to align this approach better with the current treatment of translation( set)s, one may consider to re-define vartrans:translationset as a subclass of dct:dataset (and vartrans:trans as a subproperty of dct:haspart) and to motivate it as such in a future revision of the vartrans module. this would be a backwardcompatible revision that comes without any ad-ditional overhead (i.e. newly introduced concepts). a more radical alternative would be to deprecate vartrans:translationset and to refer dct:dataset, instead. overall, we succeeded in creating our 'rosetta stone' for representative varieties of low german in the sense that there now is a humanand machine-readable lexical knowledge graph of (north low saxon) lemmas and their interdialectal links into other, externally hosted dictionaries. however, while we were using standard llod technologies to implement this interdialectal linking, we did not actually provide linguistic linked open data. our wöwö data uses resolvable uris, but it is linked with dictionaries in html, but not rdf. further, most of these linked data sources are not actually 'open' in the sense of the open definition. considering these challenges, our work represents a first step towards putting low german on the map of linguistic linked open data, and a proof-of-principle of its capabilities. a future direction may thus be to encourage or to support the colleagues developing wörterbuchnetz, dwn, and other platforms, to embrace rdf technologies, and then, to really create an interdialectal, distributed meta-dictionary of low german, and to facilitate the development of technologies and resources that benefit all its varieties in their entirety. the rdf data is publicly available from the nds spraakverarbeiden organization at github and from https://nds-spraakverarbeiden. github.io/linked-nds-dictionaries/ . note that after conversion, we had to drop the twents lemma urls from the html release, because we found these to be unstable. (the data is still included in rdf, and can be re-built from the repository any time.) we actually see this as a call to arms for the promotion of linguistic linked data and open data, as here, developer convenience and copyright restrictions force us to exclude a potentially important linguistic data set (and a speaker community) from interdialectal lexical resources and technical solutions developed on this basis.