Cookie Policy
Last updated: 27 March 2026
Current status
This site uses Google Analytics 4 (GA4) for anonymous usage statistics. Analytics cookies are set only after you give consent via the cookie banner. If you decline or ignore the banner, no cookies are set and no analytics data is collected.
What are cookies
Cookies are small text files that websites place on your device to store information. They are widely used to make websites work, to remember preferences, or to track browsing activity. This site uses cookies only for anonymous analytics, and only with your consent.
Why we have this policy
Under the EU ePrivacy Directive (Directive 2002/58/EC as amended by 2009/136/EC), the UK Privacy and Electronic Communications Regulations 2003 (PECR), the French Loi Informatique et Libertés and CNIL guidelines, the German Telekommunikation-Digitale-Dienste-Datenschutz-Gesetz (TDDDG), and the Belgian Act on Electronic Communications, websites must inform users about any cookies or similar technologies and obtain consent before setting non-essential cookies. This policy explains what cookies we use and how you can control them.
How consent works
When you first visit this site, a banner appears at the bottom of the page asking whether you accept or decline analytics cookies. Google Analytics is not loaded and no cookies are set until you click "Accept." If you click "Decline," no analytics cookies are set. Your choice is remembered in your browser's local storage so you are not asked again. You can change your mind at any time (see "How to withdraw consent" below).
Strictly necessary cookies
Strictly necessary cookies are exempt from consent requirements because they are essential for the site to function. This site does not currently set any strictly necessary cookies. Your consent preference is stored in browser local storage (not a cookie).
| Cookie name | Purpose | Duration |
|---|---|---|
| None at this time. | ||
Analytics cookies (consent required)
These cookies are set by Google Analytics 4 only after you click "Accept" on the cookie banner. They collect anonymous data about how visitors use the site. IP anonymisation is enabled. No advertising or profiling cookies are used.
| Cookie name | Purpose | Duration |
|---|---|---|
| _ga | Distinguishes unique visitors. Set by Google Analytics. | 2 years |
| _ga_KRZJPMH0YB | Maintains session state. Set by Google Analytics. | 2 years |
Google may also set short-lived cookies (such as _gid, lasting 24 hours) for session-level analytics. For full details, see Google's cookie documentation.
Local storage and similar technologies
This site uses browser local storage to remember your cookie consent preference (key: ahl_cookie_consent). This is not a cookie and does not track you. The interactive experiments use only temporary in-memory JavaScript variables that are discarded when you close or refresh the page.
How to withdraw consent
You can withdraw your consent at any time by clearing your browser's local storage for this site. In most browsers you can do this through the developer tools (Storage or Application tab) or by clearing site data in your browser's settings. After clearing, the consent banner will appear again on your next visit. You can also install the Google Analytics Opt-out Browser Add-on to block Google Analytics across all websites.
How to manage cookies in your browser
You can control cookie behaviour in your browser settings. Most browsers allow you to block all cookies, block third-party cookies, or delete cookies that have already been set. Consult your browser's help documentation for instructions specific to your browser.
Contact
If you have any questions about this cookie policy, please see the About page for contact information.