How does personalisation in search engine results work? Which signals are taken into consideration when the algorithm favorites one over another result? What is the weight of these different signals? Curious to find out, I did a small research exercise.
Crowdsourcing search results for two queries [parkland survivors] and [holiday], I gathered 91 distinct query results, from participants from 8 countries. Participants were asked to provide information on search engine used, browser used, IP address accessed (global or local) and local domains, whether accessed from desktop or mobile (and particular app used), logged in or logged out, ad blockers used or not, other extensions added to the browser (Ghostery, PrivacyBadger and similar) in order to investigate the relation between these factors and the diversity of search query outputs.