Social media algorithms: how do they tailor timelines? Drawbacks of personalised content online explained

Algorithms shape our experience of social media sites like TikTok and Instagram - but how do they work?

Algorithms are a key part of being online - but how exactly do they work? (Credit: NationalWorld/Kim Mogg)Algorithms are a key part of being online - but how exactly do they work? (Credit: NationalWorld/Kim Mogg)
Algorithms are a key part of being online - but how exactly do they work? (Credit: NationalWorld/Kim Mogg)

Have you ever been thinking about buying something online and as if by magic an advert with a relevant item soon appears in your social media feed? In the age of social media, this is a common occurrence.

From keeping up with the latest news to sharing pictures with friends and family, to organising day-to-day lives in online calendars, our online lives can rule our life in the real world. However, social media in particular has become a major part of the lives of billions of people across the world. 

Social media sites like Facebook, Instagram, TikTok and Twitter are all driven by powerful algorithms. The phrase is well-known to many, but the intricacies of how they actually shape our experience online is often a mystery. 

Algorithms dictate not only our exposure to well-timed adverts, but can have major influences on the way we see the world. 

How do algorithms work? 

Stephen McAllister, head of business intelligence at Absolute Digital Media, explains how they work: “Social media algorithms have become increasingly complex over the years and have a significant impact on our online experience. Algorithms use a range of data points, such as user activity, engagement rates, and personal preferences to curate content that they believe is most relevant and engaging to users.”

On different sites, different kinds of data can be collected. On Instagram, interaction and engagement is key to shaping how the timeline appears for each user, while on Facebook preferences - such as liked pages - also contribute to shaping the algorithm. 

McAllister added that in addition to user-posted content, social media sites “use algorithms to serve targeted ads to users based on their interests and browsing history.” Making a simple 30-second Google search for a pair of shoes, a new television or any product can result in adverts being delivered to the user on a range of sites, social media or otherwise. 

With more than 8.9 billion Google searches across the world in any one day, Google Ad spaces on sites are filled with personalised adverts, which will relate to recent searches made from your IP address. Accepting cookies on a website saves this data to the browser being used, with some of this information being sent straight to the website itself.

Algorithms ‘reinforce existing beliefs’

Algorithms are used to personalise the user experience on social media sites. While this may be appealing to those hoping to see more of their interests in their feeds, it has some major drawbacks. 

“On the one hand, they can help us discover content that is relevant and interesting to us, and connect with like-minded individuals”, explains McAllister. “On the other hand, they can also create filter bubbles, where users are only exposed to content that reinforces their existing beliefs and biases.”

In times of political tensions, elections and unrest, this ‘bubble’ effect can result in users only seeing content from those in their circles of influence. A prime example of this was during the Covid pandemic, when misinformation was widely spread about the virus and vaccines.

A study for the British Medical Journal showed that 88% of false or misleading claims on Covid-19 identified by researchers were shared by social media users. The research said: “The misleading content that received the highest engagement typically contained a small degree of accurate information that was re-contextualised and twisted; misinformation and disinformation that included doctored images and videos received the next highest.”

However, algorithms aren’t necessarily a bad thing on social media sites. “The role of algorithms in social media is complex, and their impact on our online experience is constantly evolving”, says McAllister

“We see algorithms curate content and aim to deliver a more tailored and unique experience for users in social media, to help drive more engagement, time on platforms and to get the content that is most important to them versus seeing all content all the time. 

“As algorithms continue to evolve, we expect to see more hyper personalised social media feeds.”