Privacy Policy

This is a translation for convenience; the German version is legally binding. In short: no cookies, no tracking, no analytics services and no third-party content without your click; server logs are stored with shortened IP addresses for 14 days.

1. Controller

Dr. Marc Jekel, University of Cologne, Social Psychology, Richard-Strauss-Str. 2, 50931 Cologne, Germany, marc.jekel@uni-koeln.de

2. Scope

This policy applies to marc-jekel.de and its subdomains (including apps.marc-jekel.de, projektseminar.marc-jekel.de, pcs-social.marc-jekel.de), modeling-for-everyone.eu, coherence-based-reasoning-and-rationality.de and the apps under decision-research.de. The website decision-research.de itself is operated by GoDaddy and is not covered.

3. Hosting and server logs

The pages run on a server of DigitalOcean, LLC (105 Edgeview Drive, Suite 425, Broomfield, CO 80021, USA) in its data centre in Frankfurt am Main, Germany. Data processing on my behalf is governed by DigitalOcean's Data Processing Agreement.

When you open a page, technically necessary data are processed and logged: a shortened IP address (the last digits are removed before storage), date and time, the requested address, status code, amount of data transferred, referrer and browser identifier. The logs serve secure operation, error analysis and anonymous access statistics, and are deleted automatically after 14 days. The legal basis is Art. 6(1)(f) GDPR (legitimate interest in secure and stable operation).

To protect against attacks, IP addresses from which repeated failed login attempts to the server originate are blocked temporarily.

4. Cookies and Shiny apps

The websites do not set cookies and do not use analytics or tracking services.

The interactive apps (Shiny) open a technical connection to the server for as long as you use them. Your inputs are used only for the calculations in the current session and are not stored. Files that you upload to or download from an app are processed only for that operation. The legal basis is Art. 6(1)(f) GDPR.

5. External content

Fonts, program libraries and the rendering of formulas (MathJax) are loaded from this server. No data are transmitted to third parties when you open the pages and apps.

Embedded videos from YouTube and presentations from Mentimeter are loaded only when you click “load”. Only then is your IP address transmitted to the respective provider, which processes the data under its own responsibility: Google Ireland Ltd. (YouTube, embedded via youtube-nocookie.com; data may be transferred to the USA) or Mentimeter AB (Sweden). The legal basis is your consent given by clicking (Art. 6(1)(a) GDPR).

One click applies to all embedded content from the same provider on the respective website: all videos or presentations are then loaded, and your choice is stored in your browser's local storage (localStorage, not a cookie) for this website, so that the content is loaded directly on later visits. This storage is necessary to implement your choice (§ 25(2) no. 2 TDDDG). You can withdraw your consent at any time for the future by deleting this website's data in your browser; the content will then again be loaded only after a click.

Links to other websites (e.g. GitHub, journals) transmit data only when you follow them.

6. Nextcloud

At cloud.marc-jekel.de I operate a Nextcloud for myself and invited project members. There, the data of registered users (account, uploaded files) are processed in order to provide the service; the legal basis is Art. 6(1)(b) GDPR.

7. Your rights

You have the right of access, rectification, erasure and restriction of processing of your data, the right to data portability, and the right to object to processing based on Art. 6(1)(f) GDPR. To exercise these rights, please use the address above. You also have the right to lodge a complaint with a data protection supervisory authority, for example the State Commissioner for Data Protection and Freedom of Information of North Rhine-Westphalia (Landesbeauftragte für Datenschutz und Informationsfreiheit Nordrhein-Westfalen).

Last updated: October 2026 · Legal notice