Dear colleagues, We are very pleased to announce that the GLES Open Science Challenge 2021 had a very successful start. We received over 30 submissions and we thank all the participants. However, to successfully finalize the OSC pilot project, we need your help. We need reviewers who can commit to peer-reviewing an OSC article within the following timeframe: [cid:image001.png@01D79CDA.064A5FA0] We know that this is a very tight schedule. However, to ensure that the review process is completed before the GLES data are published, and thus the articles can be published as Registered Reports, this period cannot be extended. If you are willing to review a Registered Report in your field of expertise, please fill out this brief survey<https://unipark.de/uc/gles_osc/reviewer/>. All expert reviewers are welcome, from Ph.D. students to professors. What if you are interested in becoming a reviewer but hesitate because you’ve never reviewed a Registered Report before? Not a problem. You will find clear guidelines and detailed information on the review process and criteria in our Guidelines for Reviewers<https://gles.eu/wp-content/uploads/2021/05/OSC_Guidelines_for_Reviewers-1.pdf>. Further information can be found on our website<https://gles.eu/gles-open-science-challenge-2021/>. Please do not hesitate to contact us if you have any further questions or inquiries. Thank you for your collaboration! Best Regards on behalf of The Editorial Team of the GLES Open Science Challenge 2021, Hannah Bucher ______________________________________________ Hannah Bucher German Longitudinal Election Study(GLES) GESIS - Leibniz Institute for the Social Sciences P.O.Box 12 21 55 | D-68072 Mannheim Phone: +49(621)-1246-418 Mail: Hannah.Bucher@gesis.org<mailto:Hannah.Bucher@gesis.org>