Eosc/norbert

Available Bokmål Text Corpora

• Norsk Aviskorpus; 1.7 billion words; sentences are ordered; clean;
• Norwegian Wikipedia; 160 million words; sentences are ordered; clean (more or less);
• noWAC; 700 million words; sentences are ordered; semi-clean;
• CommonCrawl from CoNLL 2017; 1.3 billion words; sentences are shuffled; not clean;
• NB Digital; 200 million words; sentences are ordered; semi-clean (OCR quality varies).

Preprocessing and Tokenization

SentencePiece library finds 157 unique characters in Norwegian Wikipedia dump.

It seems there are some tokenization issues in the UDPipe Norwegian model trained on UD 2.5 (norwegian-bokmaal-ud-2.5-191206.udpipe). It always merges punctuation marks with the preceding words, as can be checked at the online demo.

Example:

# text = På østsiden av vannet, er det en godkjent bålplass.
1	På	på	ADP	_	_	_	_	_	_
2	østsiden	østsid	NOUN	_	Definite=Def|Gender=Masc|Number=Sing	_	_	_	_
3	av	av	ADP	_	_	_	_	_	_
4	vannet,	$vannet,	PUNCT	_	_	_	_	_	_
5	er	være	AUX	_	Mood=Ind|Tense=Pres|VerbForm=Fin	_	_	_	_
6	det	det	PRON	_	Gender=Neut|Number=Sing|Person=3|PronType=Prs	_	_	_	_
7	en	en	DET	_	Gender=Masc|Number=Sing|PronType=Art	_	_	_	_
8	godkjent	godkjent	ADJ	_	Definite=Ind|Degree=Pos|Gender=Neut|Number=Sing	_	_	_	_
9	bålplass.	bålplass.	NOUN	_	Abbr=Yes	_	_	_	SpaceAfter=No

The model trained on the previous 2.4 release (norwegian-bokmaal-ud-2.4-190531.udpipe) does not exhibit such behavior.

There is an active pull request which supposedly fixes this.

Evaluation

Do we have available Norwegian test sets for typical NLP tasks to evaluate our NorBERT?