Adventures in Technology Enhanced Learning @ UoP

Tag: plagiarism

Similarity scoring is a secondary consideration for online assessment…

Similarity scoring should be a secondary consideration for online assessment. Much more important factors, from my point of view, are ease of marking for academics; access to quality feedback for students; and innovative authentic assessment workflows.

Turnitin are close to monopolising the market on similarity scoring of student papers but many assessment platforms already use Turnitin and Urkund as plugin services to provide similarity scoring.

Where should we be focusing our effort at UoP?

As an institution one of our strengths lies in quiz/question-based assessments. This is particularly the case in the Science and Technology faculties. We have a mature sophisticated platform in Moodle to deliver these types of assessments and a deep level of staff expertise across the organisation, which has developed further through-out the pandemic.

The risk factors for UoP include a need to increase capacity for online exams (or diversify some of our assessment types onto an external platform at peak periods) and the ability to be able to innovate in terms of essay/file-based assessments.

From what I can see, Turntin has stagnated in terms of assessment innovations in recent years and have not yet improved service reliability at key assessment periods by migrating their platforms to a service like AWS. This has been promised repeatedly but not delivered on as yet.

This is potentially a reason why we saw growth in Moodle assignment and quiz usage during the pandemic rather than a big increase in Turnitin usage (trust in the reliability of the service and flexibility of the functionality).

So where could we focus our effort to improve the assessment tools for educators and students to gain the most benefits?

Innovative assessment workflows

Posing a long-form question to a student and easily marking the finished product should be a simple process – and it is on platforms such as Turnitin. However, we are increasingly adapting our assessments to be more authentic: assessments that more closely match how students will operate in the workplace. This often requires more sophisticated workflows and mechanisms, which should still be straightforward for academics to engage with and make sense of if they are to be successful. 

Traditional paper-based exams (potentially bring your own device)

During the pandemic staff were forced to transition away from paper-based exams. Many exams were instead delivered as coursework or window assignments (e.g. a 2hr assignment within a 24hr window) or as question-based quiz exams. When exam halls are available again staff may revert back to previous paper-based solutions. After all, we know how these work and paper doesn’t need charging or a stable wifi connection. However, we can harness this forward momentum with a platform dedicated to supporting timed essay assignments on students’ own devices or University machines. Several platforms offer functionality for students to download assignments at the start of an exam with no need to have an internet connection until it’s time to submit at the end. This could represent a robust, safe exam experience that more closely matches how students study today. Who handwrites for three hours any more? I’d be willing to bet most students don’t.

There are challenges with BYOD (bring your own device) particularly around charging and ensuring student machines are reliable. Many of these challenges can be solved with a small stock of fully charged devices, which can be swapped out to students when needed. Chromebooks are ideal online exam devices for this very reason, due to their long battery life and simple configuration. 

Assessment feedback

Workflows such as “feedback before grades” can help students better engage with their feedback, but better access to feedback for students in a variety of places is also key.

Services that offer a holistic view of assessment feedback, or the ability to extract these comments via API so we can build our own views, are increasingly valuable. This functionality will enable key staff such as personal tutors or learning support tutors to view student feedback as a whole (rather than in silos) to spot key areas to help students improve their academic work.

To round out where I started with this post, providing similarity checking is an important part of modern assessment – but it is a problem that has already been solved, multiple times.

If we make assessment more authentic, more flexible and more collaborative there will be less need for plagiarism detection because students will be demonstrating more of the attributes we want them to leave University with. I accept this is perhaps an overly idealistic viewpoint, as there are a lot of students to assess each year, but this is more reason to explore flexible assessment solutions that can make the lives of academics and students a bit easier.

Turnitin – What’s in a number?

The University of Portsmouth uses the Turnitin service to provide facilities for plagiarism detection, online marking and as a development tool for academic writing, although most users are interesting in one thing – a number.

Contained within the Originality Report is a Similarity Score out of 100, which many users wrongly believe to a be plagiarism score with a magic number, at which in can be conclusively determined whether plagiarism has or has not occurred. The problem is, this figure can be manipulated, there will also be mitigating circumstances and lastly let us not forget the system is not perfect either – there will be some margin for error.

Crudely speaking the Similarity Score number is a percentage of the words in your document which matched text from other documents that Turnitin searched against. For shorter assignments with a direct question and consequently a more concise correct answer may well therefore see higher score when compared to a longer assignment with more scope to include to include diverse material.

The number of students in your class and whether the assignment has been set in previous years (or at different institutions) may limit the scope for truly original material, that’s not to say a very high score is necessarily acceptable however it does mean that the latest content may not be unique for genuine reasons. An assignment based upon group work is also a recipe for a higher than usual Similarity Score since students are likely to be working from the same research, data and figures so will in all likelihood draw the same conclusions.

What does Turnitin check an assignment against? There are stored student papers in both a global central repository and the University of Portsmouth own repository (where we might store more sensitive documents). Turnitin also searches against material found on the internet and can check journals, periodicals and publications. Personally I would check against everything, if the service is available, use it.

Turnitin offers several filters which may be toggled, for example whether to include or exclude bibliographic references. Personally I cannot think of a reason why you want to include bibliographic references in the Similarity Score as citing sources is a requirement of good academic writing. That said if the assignment were a lab report and references were not expected then it might be safer to include bibliographic references just in case the Turnitin software incorrectly identified a bibliography and consequently excluded all of the text that followed. You can also toggle quoted material, quotes would not normally be considered within a plagiarism report although the volume of them may indicate a lack of original content from the author. Where quoted material is excluded from the Originality Report, Turnitin helpfully points out when more than 15% of the paper is quoted material. The final filter is for small matches, usually matches of 3-4 words are rather inconsequential, you may also have longer phrases that appear repeatedly throughout the assignment – you can exclude this from being repeatedly matched and skewing the Similarity Score using the ‘exclude small matches’ filter. Personally I use all the filters, excluding bibliographic references, quoted material and small matches – I can always turn them back on later when reviewing a paper if I am suspicious.

So after searching against all of the available material, excluding bibliographic references, quoted material and small matches, what is the magic number? Well, the magic number is… the number at which you become suspicious of course!

Finally, to wrap up this post, and just in case a concerned student has stumbled across this blog post, I would like to emphasise that if they know they have not deliberately plagiarised then they have nothing to worry about. If they are concerned that they have used another source and may not have referenced it properly, then guidance is available from the Academic Skills Unit (https://kb.myport.ac.uk/Article/Index/12/4?id=2747)

 

Email: academicskills@port.ac.uk

Telephone: +44 (0)23 9284 3462

Or, visit the Academic Skills Unit in person during our opening hours:

Third floor Reception, The Nuffield Centre

St Michael’s Road

Portsmouth

PO1 2ED

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