Facebook will bring sweeping changes to its trending topics module Reuters

Facebook is revamping its news curation guidelines following an internal investigation into claims of political bias. The company announced on Monday (23 May) that it would introduce several changes to its 'Trending Topics' news module aimed at ensuring all news is treated fairly, despite finding no evidence suggesting the contrary.

Facebook has been probing claims that staff working on the website's editorial desk were instructed to suppress news stories viewed as having a conservative agenda. The allegations, which were made by anonymous sources said to be working for Facebook's trending section, also suggested that staff had a large role in determining the stories that appeared on the website's homepage, which were sourced from just a small selection of media outlets.

Following the two-week investigation, and echoing claims made by CEO Mark Zuckerberg, Facebook said there was "no evidence of systematic political bias in the selection or prominence of stories included in the Trending Topics feature". It claimed that liberal and conservative news was treated by the website with equal consideration and that most news topics propagated in the media appeared in its trending section regardless of political standing.

However Gizmodo, who kickstarted the furore around Facebook's editorial practices in early May, pointed out that the company's investigation only analysed activity at the company over the last 90 days, whereas the former curators that spoke to the website worked at Facebook from mid-2014 to December 2015.

Facebook also admitted that it "could not fully exclude the possibility of isolated improper actions or unintentional bias in the implementation of our guideline policies". In order to minimise these incidents in future, the company said it would provide refresher training for staff to encourage them against making editorial decisions "made on the basis of politics or ideology", and would update its staff guidelines to make this clearer. Additional controls and oversight around the content team will also be introduced, Facebook added.

The company will additionally eliminate its top 10 list of news outlets used to determine the importance of topics and remove the ability to assign an importance level to a topic based on its coverage in said list. Facebook admitted in its investigation report that prior to 2015, this practice may have caused some stories to have been excluded from its trending section. However, Facebook will retain its "boosting" tool, which is used by reviewers on the company's trending section to "better reflect the prominence of widely-reported topics".

This will be renamed as "topic prominence" and is not the only tool to get a rebrand: the "blacklisting" tool will be renamed "revisit", meanwhile the "injection" tool will now be known as the "topic correction" tool.

In a statement, Facebook general counsel Colin Stretch said: "This process has helped us to identify valuable improvements to our service. These improvements and safeguards are designed not only to ensure that Facebook remains a platform that is open and welcoming to all groups and individuals, but also to restore any loss of trust in the Trending Topics feature.

"We will continue to work to improve the feature, as well as to seek feedback from people who use our service to make sure we keep Facebook a platform for all ideas."