search engine personalisation

Some search engines deliver the same result no matter who is using them. However, others, notably most web search, tries to learn your interests based on previous activity and hence to produce more personalised results. This is clearly useful in areas such as music selection by streaming services, but means one is rarely exposed to choices that might stretch one's musical appreciation. Similarly, for web search this means that a search for "chihuahua" would usefully produce different results if you are a dog lover or frequent traveller. The downside is that this personalisation can lead to filter bubbles and exacerbate extreme views.