Abstract
In this article we provide an overview of first-hand experiences and vantage points for best practices from projects in seven European countries dedicated to learner corpus research (LCR) and the creation of language learner corpora. The corpora and tools involved in LCR are becoming more and more important, as are careful preparation and easy retrieval and reusability of corpora and tools.
But the lack of commonly agreed solutions for many aspects of LCR, interoperability between learner corpora and the exchange of data from different learner corpus projects remains a challenge. We show how concepts like metadata, anonymization, error taxonomies and linguistic annotations as well as tools, toolchains and data formats can be individually challenging and how the challenges can be solved.