Privacy Policy

1. Controller

The controller responsible for data processing within the meaning of the General Data Protection Regulation (GDPR) is:

2. Data Protection Officer

The Data Protection Officer of the University of Bonn can be contacted at:

3. Purpose of Processing

Powermeter is a web-based tool designed to support researchers in estimating the required sample size for quantitative studies.

The collected data is processed for the following purposes:

• improving the usability of the tool
• identifying technical issues and bugs
• understanding which features users consider missing
• improving the methodological quality of the power calculation workflow
• supporting future development of new versions of Powermeter

Users may also voluntarily provide feedback on:

• what they like or dislike
• whether bugs occurred
• which features or options they are missing

4. Categories of Data Processed

a) Anonymous usage data

When using Powermeter, we store only anonymous usage information, including:

• selected calculation parameters
• clicked options and decision paths leading to the final power estimate
• anonymized usage workflows
• voluntarily submitted textual feedback

This data is stored without any link to identifiable persons and is used solely for research and tool improvement purposes.

b) Optional email address

Users may voluntarily provide their email address if they would like to be informed about future versions or updates of Powermeter.

The email address is stored separately from anonymous usage data and cannot be linked to the selected parameters, calculation paths, or feedback history.

Providing an email address is entirely optional and based on Art. 6(1)(a) GDPR (consent).

5. AI-Supported Chat Processing via OpenAI

Powermeter includes an AI-supported chat-based workflow to assist users in selecting suitable parameters and obtaining sample size recommendations.

For this purpose, user-entered chat content is transmitted to and processed by OpenAI.

This processing is necessary to provide the AI-assisted functionality of the tool and to improve the quality of the user experience.

Users are therefore asked not to enter sensitive personal data, confidential study information, or identifying participant data into the chat.

If OpenAI processes data outside the European Union, such processing is carried out on the basis of appropriate safeguards pursuant to Art. 44 et seq. GDPR, in particular standard contractual clauses where applicable.

6. Legal Basis

The processing is based on:

• Art. 6(1)(e) GDPR – performance of a task carried out in the public interest in the context of academic research and methodological development
• Art. 6(1)(a) GDPR – consent for the voluntary submission of an email address

7. Storage Duration

Anonymous usage data and voluntarily submitted feedback are stored for 10 years.

Optional email addresses are stored until:

• the information about future versions is no longer required
• consent is withdrawn
• no later than 10 years after collection

8. Data Sharing

Data is shared only where necessary with:

• technical service providers hosting or maintaining the website
• OpenAI for the processing of chat inputs
• other recipients where disclosure is legally required

The optional email address is never combined with anonymous usage data.

9. Data Subject Rights

Under the GDPR, users have the right to:

• access their personal data
• request rectification
• request deletion
• restrict processing
• withdraw consent at any time
• lodge a complaint with a supervisory authority

Please note that these rights apply only to personal data, such as the optional email address. Fully anonymous usage data cannot be attributed to an individual and therefore cannot be accessed or deleted on a per-person basis.

10. Notice on Anonymity

The selected parameters, decision paths, and calculation workflows are stored in a way that does not allow any conclusions about the identity of individual users.

The only exception is the optional email address, which is stored separately and exclusively for update notifications.