Privacy Policy for PowerMeter Extension

last updated: May 2023

The Max Planck Institute for Intelligent Systems and the University of Tübingen are committed to protect your data and to respect your privacy. This privacy statement explains the reason for the collection and processing of your data in the context of the Powermeter Research Experiment. It explains what data is collected, the way in which it is collected, handled, and protected, how that information is used.

1. Why and how do we process your data?

Purpose of the processing operation:

Max Planck Institute for Intelligent Systems collects and further processes your data to conduct the Powermeter Research Experiment (before, during and after) and to process your registration in that experiment. Powermeter is a Chrome web-browser extension (i.e. a software application adding functionality to a web browser) designed exclusively for research purposes and distributed through the Google Chrome Store. By installing the extension, users agree to participate in a research experiment. Powermeter performs random modifications to the display or positioning of search results in popular search engines to investigate the causal effect of display and positioning on user click behavior. Powermeter does not modify individual search results or links. It only rearranges ranking, positioning, and display of search results. It does not change, modify, distribute, or otherwise alter any part of the search engines' software it operates on.

Powermeter does not collect personal data. It indexes users within the population through installation time-stamps and then counts the number of clicks occurring on search engines associated with different arrangements of content as inputted by each user. The indexing of users is necessary to understand if clicks are coming from different or from the same user and for the evaluation of statistics across different demographics. Specifically, Powermeter collects the following non-personal data: (i) the type of search engine used (Google or Bing); (iii) the version of the extension installed; (iii) the index of the search page where the click occurs; (iv) the user index; (v) the number and relative positioning of ads and specialised search results present on the page the click occurs; (vi) the relative positioning of the clicked item vis-à-vis related items object of interest; (vii) the timestamp of when the click occurred.

Beyond that, Powermeter never stores users' search query, users' identifiers (such as names, emails, IP addresses, etc.), nor records any information regarding the content of the links clicked over by users or the url of the landing page or any other data related to users' browsing activity. The use of information received from Google APIs will adhere to the Chrome Web Store User Data Policy, including the Limited Use requirements.

At the time of installation, Powermeter will present adhering users the option to answer a few multiple-choice questions concerning their gender, country, age, and language. Responding to these questions will be facultative and collected answers will only be used to evaluate and compare aggregate click statistics across demographics.

Collected data is securely transmitted (using https protocol) and stored in a database on a secure and protected webserver hosted locally by the Max Planck Institute for Intelligent Systems at its premises in Tübingen, Germany.

Communication between the research team and adherents to the experiment will only occur through in-browser one-way (from the extension to the extension user) pop-up messages. Members of the research team will not be able to individually contact adherent users as they neither know who they are, nor are aware of their contact details.

The processing operations are linked to the organisation, functioning, and management, and follow-up to the Powermeter Research Experiment. Processing operations are limited to what is strictly necessary for the management and functioning of the Powermeter Research Experiment. Nevertheless, the Max Planck Institute for Intelligent Systems according to § 25 (1) TTDSG (Telekommunikation-Telemedien-Datenschutz-Gesetz) requires adhering users to consent to the collection and processing of their data. Consequently, by downloading and installing the Powermeter extension on the Chrome store you are giving us your explicit consent to:

  • Collect, store, and process your dedicated numeric installation time-stamp index;
  • Collect, store, and process your clicks associated with different arrangements of content on,, and;
  • Collect, store, and process the answer(s) you will voluntarily disclose concerning your gender, age, location, and language in the onboarding form;
  • Receive pop-up messages for any relevant communication related to the management, functioning, and termination of the Powermeter Research Experiment and to receive the messages hardcoded within the extension.

Data collection does only begin after Powermeter has been successfully installed.

Your consent can be withdrawn for the future at any time by uninstalling the extension.

Your data will be used for the Powermeter Research Experiment only. Your data will not be shared, distributed, or repurposed.

Which personal data do we collect and further process?

No personal data will be collected or processed.

How long do we keep your data?

Your non-personal data will be only kept for the time strictly necessary to fulfil the purpose of collection or further processing.

All data related to the organisation and management of the Powermeter Research Experiment (this includes the information given during the registration, before, and during the experiment) will be deleted after the termination of the research project and within six months at the latest after the last action relating to the research project occurred.

How do we protect and safeguard your data?

All data are collected in electronic format, encrypted as described in Section n. 2, and stored on a secure and protected webserver hosted locally by the Max Planck Institute for Intelligent Systems at its premises in Tübingen, Germany. Access to the server is restricted and controlled.

Who has access to your data and to whom is it disclosed?

Access to your data is provided to the Max Planck Institute for Intelligent Systems staff responsible for carrying out this processing operation and to other vetted and authorised researchers of the Tübingen University according to the “need to know” principle. The data we collect will neither be shared, nor transferred to any third party, and will not be repurposed.

What are your rights and how can you exercise them?

As an adherent user you are given the prerogative to interrupt the collection and processing of your data at any time by uninstalling the extension. The withdrawal of your consent will not affect the lawfulness of the processing carried out before you have withdrawn the consent.