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Frequently Asked Questions

What is assessment data forensics (ADF)?

Assessment data forensics is a set of statistical research methods for detecting potential fraud in candidates’ examination data in a highly reliable way.

What is aberrant response behaviour?

Aberrant response behaviour is a deviation from answering behaviour which is regarded as average or normal. The characteristic of an aberrant response pattern is that in principle, it seldom occurs in an exam.

What are fraud indices?

Fraud indices are calculated using algorithms, and provide a numerical value for the probability of examination fraud. Among them: response time, answer changing behaviour and the Guttman score.

What is response time?

Response time is the time someone needs to provide an answer to an examination question.

What is answer changing behaviour?

Answer changing behaviour is the (repeated) revision of the answer to an examination question.

What is the Guttman score?

The Guttman score is a statistical index expressing how extreme a candidate is in the ratio between answering easy and difficult questions correctly.

What is the ADF monitor?

The ADF monitor is a reliable measurement of your examination data with the Xquiry software tool, to monitor whether there have been incidences of cheating during an exam.

What is the ADF protocol?

The ADF protocol is a quality evaluation model focusing on fraud prevention and detection. Its points of departure are the examination material, the ADF standards and the results from the ADF monitor.

What is the ADF qualifier?

The ADF qualifier is an organisation which applies the continuous Xquiry improvement cycle, where we deploy the EDF monitor repetitively to measure the effect of the EDF protocol. The objective is to secure the reliability and validity of your examination procedure.

When should I use assessment data forensics?

Assessment data forensics is useful to those who attach value to the trustworthiness of an exam.

How many readings do I need to be able to apply assessment data forensics?

To apply assessment data forensics, the individual examination items must be conducted at least 250 times.

Can assessment data forensics be used for all types of exams?

In principle, assessment data forensics can be applied to all types of exam, both on paper and digital, random or fixed. Even to examinations with open questions.

Do I need an advanced (digital) testing system to enable assessment data forensics analysis?

No, we can even analyse data from paper exams which have been transferred to an Excel file. However, there are certain methods which cannot be implemented if no data is available for them. This may include a lack of data on the response time for a paper exam.

What does assessment data forensics cost?

The cost of assessment data forensics cannot be stated directly, because it depends among other things on the type of data, the number of candidates and the number of examinations. Would you like to know what it will cost? Then please contact us.

How can I transfer the data for analysis?

For incidental analyses you can upload an Excel file in a secure environment (FTPS server). For structural analyses we can link your software to the Xquiry database. We will be happy to discuss the options.

Why do you need my personal data?

We need personal data for registrations, notifications, invoices and for certifications. Our privacy statement states how we (as data processor) deal with your privacy.

Can I see, change or delete my data?

You have the right to access your data, correct it or delete it. For such a request, please contact us via  To prevent misuse, we can ask you to identify yourself. You will receive a response within 4 weeks.

How do I get in touch with the Data Protection Officer?

You can contact our Data Protection Officer via

Want to learn more?


Download the white paper for more extensive information about assessment data forensics, or contact us if you would like to know what Xquiry can do for you.