This paper reports on efforts to improve the Oslo-Bergen Tagger for Norwegian morphological tagging. We train two deep neural network-based taggers using the recently introduced Norwegian pre-trained encoder (a BERT model for Norwegian). The first network is a sequence-to-sequence encoder-decoder and the second is a sequence classifier. We test both these configurations in a hybrid system where they combine with the existing rule-based system, and on their own. The sequence-to-sequence system performs better in the hybrid configuration, but the classifier system performs so well that combining it with the rules is actually slightly detrimental to performance.

This paper presents the NDC Treebank of spoken Norwegian dialects in the Bokmål variety of Norwegian. It consists of dialect recordings made between 2006 and 2012 which have been digitised, segmented, transcribed and subsequently annotated with morphological and syntactic analysis. The nature of the spoken data gives rise to various challenges both in segmentation and annotation. We follow earlier efforts for Norwegian, in particular the LIA Treebank of spoken dialects transcribed in the Nynorsk variety of Norwegian, in the annotation principles to ensure interusability of the resources. We have developed a spoken language parser on the basis of the annotated material and report on its accuracy both on a test set across the dialects and by holding out single dialects.

The present article presents four experiments with two different methods for measuring dialect similarity in Norwegian: the Levenshtein method and the neural long short term memory (LSTM) autoencoder network, a machine learning algorithm. The visual output in the form of dialect maps is then compared with canonical maps found in the dialect literature. All of this enables us to say that one does not need fine-grained transcriptions of speech to replicate classical classification patterns.

This paper describes an evaluation of five data-driven part-of-speech (PoS) taggers for spoken Norwegian. The taggers all rely on different machine learning mechanisms: decision trees, hidden Markov models (HMMs), conditional random fields (CRFs), long-short term memory networks (LSTMs), and convolutional neural networks (CNNs). We go into some of the challenges posed by the task of tagging spoken, as opposed to written, language, and in particular a wide range of dialects as is found in the recordings of the LIA (Language Infrastructure made Accessible) project. The results show that the taggers based on either conditional random fields or neural networks perform much better than the rest, with the LSTM tagger getting the highest score.

We present the development of a Norwegian Academic Wordlist (AKA list) for the Norwegian Bokmäl variety. To identify specific academic vocabulary we developed a 100-million-word academic corpus based on the University of Oslo archive of digital publications. Other corpora were used for testing and developing general word lists. We tried two different methods, those of Carlund et al. (2012) and Gardner & Davies (2013), and compared them. The resulting list is presented on a web site, where the words can be inspected in different ways, and freely downloaded.

The Norwegian Dependency Treebank is a new syntactic treebank for Norwegian Bokmäl and Nynorsk with manual syntactic and morphological annotation, developed at the National Library of Norway in collaboration with the University of Oslo. It is the first publically available treebank for Norwegian. This paper presents the core principles behind the syntactic annotation and how these principles were employed in certain specific cases. We then present the selection of texts and distribution between genres, as well as the annotation process and an evaluation of the inter-annotator agreement. Finally, we present the first results of data-driven dependency parsing of Norwegian, contrasting four state-of-the-art dependency parsers trained on the treebank. The consistency and the parsability of this treebank is shown to be comparable to other large treebank initiatives.

In this paper, we describe the Nordic Dialect Corpus, which has recently been completed. The corpus has a variety of features that combined makes it an advanced tool for language researchers. These features include: Linguistic contents (dialects from five closely related languages), annotation (tagging and two types of transcription), search interface (advanced possibilities for combining a large array of search criteria and results presentation in an intuitive and simple interface), many search variables (linguistics-based, informant-based, time-based), multimedia display (linking of sound and video to transcriptions), display of results in maps, display of informant details (number of words and other information on informants), advanced results handling (concordances, collocations, counts and statistics shown in a variety of graphical modes, plus further processing). Finally, and importantly, the corpus is freely available for research on the web. We give examples of both various kinds of searches, of displays of results and of results handling.

We will look at how maps can be integrated in research resources, such as language databases and language corpora. By using maps, search results can be illustrated in a way that immediately gives the user information that words or numbers on their own would not give. We will illustrate with two different resources, into which we have now added a Google Maps application: The Nordic Dialect Corpus (Johannessen et al. 2009) and The Nordic Syntactic Judgments Database (Lindstad et al. 2009). We have integrated Google Maps into these applications. The database contains some hundred syntactic test sentences that have been evaluated by four speakers in more than hundred locations in Norway and Sweden. Searching for the evaluations of a particular sentence gives a list of several hundred judgments, which are difficult for a human researcher to assess. With the map option, isoglosses are immediately visible. We show in the paper that both with the maps depicting corpus hits and with the maps depicting database results, the map visualizations actually show clear geographical differences that would be very difficult to spot just by reading concordance lines or database tables.