marpot writes "Does your school/university check your homeworks/theses for plagiarism? Nowadays, probably Yes, but are they doing it properly? Little is known about plagiarism detection accuracy, which is why we conduct a competition on plagiarism detection, sponsored by Yahoo! We have set up a corpus of artificial plagiarism which contains plagiarism with varying degrees of obfuscation, and translation plagiarism from Spanish or German source documents. A random plagiarist was employed who attempts to obfuscate his plagiarism with random sequences of text operations, e.g., shuffling, deleting, inserting, or replacing a word. Translated plagiarism is created using machine translation."