DEplain-web-sent: A corpus for German Sentence Simplification

DEplain-web-sent is a subcorpus of DEplain Stodden et al., 2023 for evaluation of sentence simplification. The corpus consists of 1846 sentence pairs of 147 parallel documents crawled from the web in standard German and plain German (or easy-to-read German). All documents are either published under an open license, or the copyright holders gave us permission to share the data. Human annotators sentence-wise aligned the 147 documents of the test set to build a corpus for sentence simplification. For the document-level version of this corpus, please see https://huggingface.co/datasets/DEplain/DEplain-web-doc.

Due to the small size of the sentence pairs, we only provide a test set for evaluation of text simplification models. If you are interested in a larger corpus, please check our paper and the provided web crawler and alignment methods to extend the corpus. You can find this data here: https://github.com/rstodden/DEPlain/. If you use the automatically aligned data, please use it cautiously, as the alignment quality might be error-prone.

Dataset Card for DEplain-web-sent

Dataset Summary

DEplain-web (Stodden et al., 2023) is a dataset for the evaluation of sentence and document simplification in German. All texts of this dataset are scraped from the web. All documents were licenced with an open license. The simple-complex sentence pairs are manually aligned. This dataset only contains a test set. For additional training and development data, please scrape more data from the web using a web scraper for text simplification data and align the sentences of the documents automatically using, for example, MASSalign by Paetzold et al. (2017).

Supported Tasks and Leaderboards

The dataset supports the evaluation of text-simplification systems. Success in this task is typically measured using the SARI and FKBLEU metrics described in the paper Optimizing Statistical Machine Translation for Text Simplification.

Languages

The texts in this dataset are written in German (de-de). The texts are in German plain language variants, e.g., plain language (Einfache Sprache) or easy-to-read language (Leichte Sprache).

Domains

The texts are from 6 different domains: fictional texts (literature and fairy tales), bible texts, health-related texts, texts for language learners, texts for accessibility, and public administration texts.

Dataset Structure

Data Access

• The dataset is licensed with different open licenses dependent on the subcorpora.

Data Instances

• document-simplification configuration: an instance consists of an original document and one reference simplification.
• sentence-simplification configuration: an instance consists of an original sentence and one manually aligned reference simplification. Please see https://huggingface.co/datasets/DEplain/DEplain-web-sent.
• sentence-wise alignment configuration: an instance consists of original and simplified documents and manually aligned sentence pairs. In contrast to the sentence-simplification configurations, this configuration contains also sentence pairs in which the original and the simplified sentences are exactly the same. Please see https://github.com/rstodden/DEPlain

Data Fields

data field	data field description
original	an original text from the source dataset
simplification	a simplified text from the source dataset
pair_id	document pair id
complex_document_id (on doc-level)	id of complex document (-1)
simple_document_id (on doc-level)	id of simple document (-0)
original_id (on sent-level)	id of sentence(s) of the original text
simplification_id (on sent-level)	id of sentence(s) of the simplified text
domain	text domain of the document pair
corpus	subcorpus name
simple_url	origin URL of the simplified document
complex_url	origin URL of the simplified document
simple_level or language_level_simple	required CEFR language level to understand the simplified document
complex_level or language_level_original	required CEFR language level to understand the original document
simple_location_html	location on hard disk where the HTML file of the simple document is stored
complex_location_html	location on hard disk where the HTML file of the original document is stored
simple_location_txt	location on hard disk where the content extracted from the HTML file of the simple document is stored
complex_location_txt	location on hard disk where the content extracted from the HTML file of the simple document is stored
alignment_location	location on hard disk where the alignment is stored
simple_author	author (or copyright owner) of the simplified document
complex_author	author (or copyright owner) of the original document
simple_title	title of the simplified document
complex_title	title of the original document
license	license of the data
last_access or access_date	data origin data or data when the HTML files were downloaded
rater	id of the rater who annotated the sentence pair
alignment	type of alignment, e.g., 1:1, 1:n, n:1 or n:m

Data Splits

DEplain-web contains a training set, a development set and a test set. The dataset was split based on the license of the data. All manually-aligned sentence pairs with an open license are part of the test set. The document-level test set, also only contains the documents which are manually aligned. For document-level dev and test set the documents which are not aligned or not public available are used. For the sentence-level, the alingment pairs can be produced by automatic alignments (see Stodden et al., 2023).

Document-level:

	Train	Dev	Test	Total
DEplain-web-manual-open	-	-	147	147
DEplain-web-auto-open	199	50	-	279
DEplain-web-auto-closed	288	72	-	360
in total	487	122	147	756

Sentence-level:

	Train	Dev	Test	Total
DEplain-web-manual-open	-	-	1846	1846
DEplain-web-auto-open	514	138	-	652
DEplain-web-auto-closed	767	175	-	942
in total	1281	313	1846

subcorpus	simple	complex	domain	description	\ doc.
EinfacheBücher	Plain German	Standard German / Old German	fiction	Books in plain German	15
EinfacheBücherPassanten	Plain German	Standard German / Old German	fiction	Books in plain German	4
ApothekenUmschau	Plain German	Standard German	health	Health magazine in which diseases are explained in plain German	71
BZFE	Plain German	Standard German	health	Information of the German Federal Agency for Food on good nutrition	18
Alumniportal	Plain German	Plain German	language learner	Texts related to Germany and German traditions written for language learners.	137
Lebenshilfe	Easy-to-read German	Standard German	accessibility		49
Bibel	Easy-to-read German	Standard German	bible	Bible texts in easy-to-read German	221
NDR-Märchen	Easy-to-read German	Standard German / Old German	fiction	Fairytales in easy-to-read German	10
EinfachTeilhaben	Easy-to-read German	Standard German	accessibility		67
StadtHamburg	Easy-to-read German	Standard German	public authority	Information of and regarding the German city Hamburg	79
StadtKöln	Easy-to-read German	Standard German	public authority	Information of and regarding the German city Cologne	85

: Documents per Domain in DEplain-web.

domain	avg.	std.	interpretation	\ sents	\ docs
bible	0.7011	0.31	moderate	6903	3
fiction	0.6131	0.39	moderate	23289	3
health	0.5147	0.28	weak	13736	6
language learner	0.9149	0.17	almost perfect	18493	65
all	0.8505	0.23	strong	87645	87

: Inter-Annotator-Agreement per Domain in DEplain-web-manual.

operation	documents	percentage
rehphrase	863	11.73
deletion	3050	41.47
addition	1572	21.37
identical	887	12.06
fusion	110	1.5
merge	77	1.05
split	796	10.82
in total	7355	100

: Information regarding Simplification Operations in DEplain-web-manual.

Dataset Creation

Curation Rationale

Current German text simplification datasets are limited in their size or are only automatically evaluated. We provide a manually aligned corpus to boost text simplification research in German.

Source Data

Initial Data Collection and Normalization

The parallel documents were scraped from the web using a web scraper for text simplification data. The texts of the documents were manually simplified by professional translators. The data was split into sentences using a German model of SpaCy. Two German native speakers have manually aligned the sentence pairs by using the text simplification annotation tool TS-ANNO by Stodden & Kallmeyer (2022).

Who are the source language producers?

The texts of the documents were manually simplified by professional translators. See for an extensive list of the scraped URLs see Table 10 in Stodden et al. (2023).

Annotations

Annotation process

The instructions given to the annotators are available here.

Who are the annotators?

The annotators are two German native speakers, who are trained in linguistics. Both were at least compensated with the minimum wage of their country of residence. They are not part of any target group of text simplification.

Personal and Sensitive Information

No sensitive data.

Considerations for Using the Data

Social Impact of Dataset

Many people do not understand texts due to their complexity. With automatic text simplification methods, the texts can be simplified for them. Our new training data can benefit in training a TS model.

Discussion of Biases

no bias is known.

Other Known Limitations

The dataset is provided under different open licenses depending on the license of each website were the data is scraped from. Please check the dataset license for additional information.

Additional Information

Dataset Curators

DEplain-APA was developed by researchers at the Heinrich-Heine-University Düsseldorf, Germany. This research is part of the PhD-program Online Participation'', supported by the North Rhine-Westphalian (German) funding scheme Forschungskolleg''.

Licensing Information

The corpus includes the following licenses: CC-BY-SA-3, CC-BY-4, and CC-BY-NC-ND-4. The corpus also include a "save_use_share" license, for these documents the data provider permitted us to share the data for research purposes.

Citation Information

@inproceedings{stodden-etal-2023-deplain,
    title = "{DE}-plain: A German Parallel Corpus with Intralingual Translations into Plain Language for Sentence and Document Simplification",
    author = "Stodden, Regina  and
      Momen, Omar  and
      Kallmeyer, Laura",
    booktitle = "Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics",
    month = jul,
    year = "2023",
    address = "Toronto, Canada",
    publisher = "Association for Computational Linguistics",
    notes = "preprint: https://arxiv.org/abs/2305.18939",
}

This dataset card uses material written by Juan Diego Rodriguez and Yacine Jernite.