Tutorial: Turnitin iThenticate Integration
Role: Journal Manager / Site Administrator
Time: 20–40 minutes
OJS Version: 3.5+
OJS supports plagiarism screening through two related services:
| Service | Provider | Access |
|---|---|---|
| CrossRef Similarity Check | CrossRef (powered by iThenticate) | Requires CrossRef membership; lower cost |
| iThenticate (direct) | Turnitin / Turnitin iThenticate | Direct Turnitin contract |
This tutorial covers both options using the Plagiarism plugin for OJS.
Before You Start
- You have Site Administrator access in OJS.
- You have iThenticate credentials from either CrossRef (Similarity Check) or Turnitin directly.
- CrossRef Similarity Check: available to CrossRef members; sign up at crossref.org/services/similarity-check/.
- Turnitin iThenticate: purchase at turnitin.com/products/ithenticate.
Step 1 — Install the Plagiarism Plugin
- Log in as Site Administrator.
- Go to Administration → Plugin Gallery.
- Search for Plagiarism.
- Click Install.
Alternatively, download from github.com/pkp/plagiarism and upload to /plugins/generic/plagiarism/.
Step 2 — Enable the Plugin
- Go to Administration → Site Settings → Plugins → Installed Plugins.
- Find Plagiarism Check and toggle to Enabled.
tip
The plagiarism plugin is configured at the Site Administrator level, not per journal.
Step 3 — Configure Plugin Settings
- Click the Settings icon next to the Plagiarism Check plugin.
- Select your service:
For CrossRef Similarity Check
| Field | Value |
|---|---|
| Service | Select iThenticate |
| iThenticate API URL | https://api.ithenticate.com/rpc |
| Username | Your CrossRef Similarity Check / iThenticate username |
| Password | Your iThenticate password |
For Turnitin iThenticate (Direct)
| Field | Value |
|---|---|
| Service | Select iThenticate |
| iThenticate API URL | https://api.ithenticate.com/rpc |
| Username | Your Turnitin iThenticate email |
| Password | Your Turnitin iThenticate password |
-
Configure when submissions are checked:
- Check on submission — runs automatically when an author submits
- Check manually — editors trigger the check from the submission dashboard
-
Click Save.
Step 4 — Running a Plagiarism Check
Automatic Check (if configured)
When an author submits, OJS automatically sends the submission file to iThenticate and records the similarity score in the submission record.
Manual Check
- Open a submission in the editorial workflow.
- In the Submission or Review stage, click Check for Plagiarism (button visible to editors/journal managers).
- OJS submits the file to iThenticate.
- Wait a few minutes, then refresh the page to see the Similarity Score.
- Click the score to open the full iThenticate report in a new tab.
Step 5 — Interpreting Similarity Scores
| Score Range | Interpretation |
|---|---|
| 0–15% | Generally acceptable; minor overlap (references, common phrases) |
| 16–30% | Review carefully; may be acceptable if overlap is from references |
| 31–50% | Significant concern; requires editorial review |
| >50% | High similarity; likely requires rejection or major revision |
Use your journal's editorial policy to define the acceptable threshold.
Troubleshooting
| Problem | Solution |
|---|---|
| Plugin not sending files | Check credentials; ensure OJS server can make outbound HTTPS requests |
| Similarity score not appearing | Allow 5–10 minutes for iThenticate to process; then refresh |
| API authentication error | Verify username and password; reset iThenticate password if needed |
| Plugin not in Plugin Gallery | Install manually from GitHub |
Next Steps
- CrossRef DOI Setup — integrate with CrossRef for DOI-based similarity detection
- Plugins Reference — overview of all OJS plugins
- Workflow Settings — configure submission requirements and editorial workflow