The MERLIN corpus is a written learner corpus for Czech, German,and Italian that has been designed to illustrate the Common European Framework of Reference for Languages (CEFR) with authentic learner data. The corpus contains 2,290 learner texts produced in standardized language certifications covering CEFR levels A1-C1. The MERLIN annotation scheme includes a wide range of language characteristics that enable research into the empirical foundations of the CEFR scales and provide language teachers, test developers, and Second Language Acquisition researchers with concrete examples of learner performance and progress across multiple proficiency levels. For computational linguistics, it provide a range of authentic learner data for three target languages, supporting a broadening of the scope of research in areas such as automatic proficiency classification or native language identification. The annotated corpus and related information will be freely available as a corpus resource and through a freely accessible, didactically-oriented online platform.

We introduce the KoKo corpus, a collection of German L1 learner texts annotated with learner errors, along with the methods and tools used in its construction and evaluation. The corpus contains both texts and corresponding survey information from 1,319 pupils and amounts to around 716,000 tokens. The evaluation of the performed transcriptions and annotations shows an accuracy of orthographic error annotations of approximately 80% as well as high accuracies of transcriptions (>99%), automatic tokenisation (>99%), sentence splitting (>96%) and POS-tagging (>94%). The KoKo corpus will be published at the end of 2014. It will be the first accessible linguistically annotated German L1 learner corpus and a valuable source for research on L1 learner language as well as for teachers of German as L1, in particular with regards to writing skills.