Turnitin (stylized as turnitin) is an Internet-based plagiarism detection service run by the American company Turnitin, LLC, a subsidiary of Advance Publications. Founded in 1998, it sells its licenses to universities and high schools who then use the software as a service (SaaS) website to check submitted documents against its database and the content of other websites with the aim of identifying plagiarism. Results can identify similarities with existing sources and can also be used in formative assessment to help students learn to avoid plagiarism and improve their writing. Students may be required to submit work to Turnitin as a requirement of taking a certain course or class. The software has been a source of controversy, with some students refusing to submit, arguing that requiring submission implies a presumption of guilt. Some critics have alleged that use of this proprietary software violates educational privacy as well as international intellectual-property laws, and exploits students' works for commercial purposes by permanently storing them in Turnitin's privately held database. Turnitin, LLC also runs the informational website plagiarism.org and offers a similar plagiarism-detection service for newspaper editors and book and magazine publishers called iThenticate. Other tools included with the Turnitin suite are GradeMark (online grading and corrective feedback) and PeerMark (student peer-review service). In March 2019, Advance Publications acquired Turnitin, LLC for . In the UK the service is supported and promoted by JISC as 'Plagiarism Detection Service Turnitin UK'. The Service is operated by iParadigms, in conjunction with Northumbria Learning, the European reseller of the Service. Functionality The Turnitin software checks for potentially unoriginal content by comparing submitted papers to several databases using a proprietary algorithm. It scans its own databases and also has licensing agreements with large academic proprietary databases. Student-paper database The essays submitted by students are stored in a database used to check for plagiarism. This prevents one student from using another student's paper, by identifying matching text between papers. In addition to student papers, the database contains a copy of the publicly accessible Internet, with the company using a web crawler to continually add content to Turnitin's archive. It also contains commercial and/or copyrighted pages from books, newspapers, and journals. Classroom integration If requested by teachers, students can upload their papers directly to the service, for teachers to access them there. Teachers may also submit student papers to Turnitin.com as individual files, by bulk upload, or as a ZIP