Turnitin is an application that helps support the development of a students' academic skills in preparing written assignments. It is designed to detect the unethical use/presentation of information in documents submitted by students.
The Student QuickStart Guide will help you get started with Turnitin and will walk you through the steps for submitting your first paper. To begin, you need to first register with Turnitin and create a user profile.
http://turnitin.com/en_us/training/student-training/student-quickstart-guide
This video will take a student through creating a new account in Turnitin and enrolling in a class. In order to enroll in a class the student must have the class id and enrollment password which can only be distributed by the class instructor. Students can enroll in multiple classes from the same user profile.
As students are completing their research papers, this question comes up often… When using TURNITIN What percentages are safe?
Well the advice is that There are no clear cut rules for this as all work will probably contain some words from other sources.
As a guide, a returned percentage of below 15% would probably indicate that plagiarism has not occurred. However, if the matching text is one continuous block this could still be considered plagiarism. A high percentage would probably be anything over 25% (Yellow, orange or red). Again this will depend on the students work and the requirements of the report or essay.
Source - Guidelines for staff and graduate students on plagiarism
Papers submitted to Turnitin may be compared against billions of internet documents, archived internet data that is no longer available on the live web, a local repository of previously submitted papers, and subscription repository of periodicals, journals, and publications. The comparison may be against any or all of these repositories as set on a specific assignment by the instructor of the class. The comparison document is called an Originality Report. This document details the matching or similar text between a submission made on Turnitin and the documents the submission was compared against.
For help with understanding and interpreting Originality Reports generated by Turnitin, on the page with the Originality Report, click the help button toward the upper right. There you will find Turnitin’s best information for working with and interpreting reports.