A number of colleagues have enquired about the accuracy and reliability of the Turnitin word-count. I have found it to be very reliable in that it is consistent, but there a number of variables which have to be taken into account. The format of the submitted document and the use of footnotes can produce different results.
To investigate and demonstrate this I created and uploaded four documents. Of these, two were in .doc format and two were PDFs. One of each format used footnotes. A word-count was taken in MS Word before submitting to Turnitin.
The results are tabulated and analysed below:
- A submission in Word format without footnotes is 100% accurate
- A submission in PDF format without footnotes overestimates by 0.2%
- A submission in Word format with footnotes is accurate but only the body of the text is counted, and not the footnotes
- A submission in PDF format with footnotes counts both body text and footnotes, but overestimates by 2.2%
The investigation found that Turnitin is accurate, but tends to over-estimate where documents have been saved as PDFs. This is more pronounced when footnotes have been used. Footnotes are counted in PDF documents but are not counted when submitted as part of a word document.
For more information and advice on the use of Turnitin, including online marking and feedback with Grademark, please visit http://tiny.cc/turnitin-staff (requires RHUL log-on credentials).