Plagiarism Prevention Crot Settings

From MoodleDocs

MS Application ID key

You need to obtain the MS Application ID key from Microsoft to use the global search features. Open one of the following links to get the ID : or

and follow the instructions to get the App ID.

Installation of the plugin

Installation using a Zip file

Download the zip:

Then Extract these files into a new folder under /plagiarism/crot and visit the Admin > Notifications page in Moodle to trigger the upgrade scripts

Global Configuration of Crot

  1. Ensure Settings > Site admin > Server > Environment indicates you have curl and SOAP installed
  2. Go to Settings > Site admin > Advanced Features find the setting “Enable plagiarism plugins” - make sure the box is ticked
  3. Go to Settings > Site administration > Plugins > Plagiarism Prevention > Crot
  4. set the following:
    • Tick the box "Use Crot"
    • Select Test global search to run a quick test of global search. If it works you will see results of test search query on the next step.
    • We would really appreciate if you check Registration option and complete simple registration form. We are doing this continious survey to apply for funding to support project development.
    • Click Save Changes button

Other Settings

  1. Student disclosure: This text will appear on the assignment submission page when student work will be uploaded to the system.
  2. Grammar size is size of text used to calculate one hash in document fingerprint. Recommended value is 30.
  3. Window size represents how granular tech search will be. Recommended value is 60.
  4. Colours are used for highlighting of similar text fragments in the side by side comparison of documents. But at the moment colouring function works only with the one colour (#FF0000).
  5. Max Distance between hashes in the text cluster: This parameter is used for allocation of hashes into text clusters in the colouring of similar text fragments. Recommended value is 100.
  6. Minimum cluster size is a minimum number of hashes in the text cluster used for colouring of similar text fragments. Recommended value is 2.
  7. Default Threshold: Assignments with similarity score less than threshold value are not displayed on Anti-Plagiarism - Assignments page.
  8. Global search threshold reserved for future development. Recommended value is 90.
  9. Global Search Query Size is the number of words in the query for global search. Recommended value is 7.
  10. Percentage of search queries for Web search is randomly selected percentage of queries from all search queries for Web search. Recommended value is 40.
  11. Number of web documents to be downloaded: How many web documents will be downloaded to your server from the list of possible sources on the web. Recommended value is 10.
  12. Culture info for global search: Culture information is used in queries for Bing search engine.
  13. Maximum file size: Files with the size more than this value are not downloaded from the internet. Recommended value is 1000000.


  1. 1. Login as a teacher to Moodle.
  2. 2. Go to the course, then to the assignment that you want to be processed by the antiplagiarism plugin. At the moment the plugin works with the following types of assignments:
  3. - Advanced uploading of files
  4. 3. Click Assignment administration/Edit settings link.
  5. 4. In the Crot block set up search parameters.
  6. 5. Save settings and wait for the cron scheduler to process the assignments.
  7. IMPORTANT: setting cron on Moodle is covered in Moodle doc:
  8. If you are not sure how cron works on your server please ask your system administrator about it.
  9. Processing may consume a lot of time: it depends on the server power and external channel bandwidth.
  10. Global search consumes more time as it requires querying the search engine and downloading similar files from the Internet.
  11. 6. Go to the assignment, click "View submitted assignments" link and you will see the maximum similarity score for submitted files.
  12. 7. Open the link with similarity score and compare documents.