What is an algorithm and why do tech companies use them?

You may have heard the likes of Google and Twitter talking about algorithms a lot in recent years.

Algorithms are by no means new – these days the term is frequently mentioned by technology-based companies that deal with data.

Why are algorithms in the spotlight?

Algorithms are in the news at the moment largely because of accusations of bias.

US President Donald Trump and a number of Republicans have accused Twitter of shadow-banning some members – an act where someone’s visibility to the public is reduced – which Twitter has denied.

In a hearing with a US senate committee this week, Twitter chief executive Jack Dorsey said that algorithms “unfairly” filtered 600,000 accounts, including some belonging to members of Congress.

Mr Trump has also taken aim at Google, saying that results on the search engine are “rigged” to show negative news about him.

Google has denied any wrongdoing, stating that it never ranks search results to manipulate political sentiment.

So what are algorithms?

Essentially, algorithms are a set of rules that a computer system follows, which can become very complicated, in order to solve a problem.

“These can become highly complex, but at their heart they remain a set of individual rules running one after the other,” explained Oli Marlow Thomas, founder of algorithm specialists Ad-Lib Digital.

“Creative performance – online advertising and content – requires lots of different data points to help achieve this.”

(Yui Mok/PA)
(Yui Mok/PA)

Google, for example, will use a number of factors to provide you with the best result for your search, weighing up everything from a website’s credibility to keywords contained on the page.

“Facebook’s algorithm is heavily weighted to promote posts with high levels of interaction ahead of more recent posts which is why you often see older posts at the top of your feed,” said Stuart Toller, director at technical consultancy agency DAM Digital.

“Facebook has decided that you’re more likely to be interested in a post that a lot of people have reacted to or commented on than a new post with no interaction.”

Website owners do their best to learn what works and what doesn’t on Google, in order to rank as close to the top as possible – this is known as search engine optimisation.

(Andrew Matthews/PA)
(Andrew Matthews/PA)

Are algorithms made public?

Some companies make their algorithms public but they are not simple reads.

Google carries out tweaks to its search engine algorithm all the time and releases updates on the bigger changes it has in place.

What next?

Mr Trump has said he intends to address what he calls digital giants “controlling what we can and cannot see”.

Meanwhile, there are intensified calls for social media giants to be regulated – all of which would have an impact on the algorithms currently in use.

(Niall Carson/PA)
(Niall Carson/PA)

“Search engine algorithms are so complex and take into account so many factors that testing their claim of non-manipulation without access to their code would be almost impossible,” Stuart added.

“And obtaining the code of Google’s search engine would be a challenge – even for Mr Trump!”

- Press Association

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