3 August 2019 | New Scientist | 9Analysis Social mediaFACEBOOK is attempting to stop
the spread of fake news on its site,
but it needs to ramp up its efforts
and be more transparent about
whether they are working. That is
the conclusion of a report released
on Tuesday by UK fact-checking
charity Full Fact, which details the
first six months of a partnership
with Facebook.
Full Fact is one of more than
50 fact-checking firms working
with Facebook to review and
debunk false content on the
site. The tech giant started
collaborating with fact-checkers
in the US in December 2016,
after criticism of its failure to stem
the spread of fake news in the
run-up to the presidential election.
Under the scheme,
Facebook provides independent
fact-checkers with content to
review and rate. Fact-checked
content is automatically marked
on Facebook, so users are
informed if they share a post
that has been reviewed. Stories,
images and videos that have been
rated as false are still shareable
but are shown lower in newsfeeds
by Facebook’s algorithm, with
the aim of reducing their reach.An analysis by Buzzfeed News
last year found that the top 50
fake stories on Facebook in 2018
generated around 22 million total
shares, reactions and comments.
Between January and June,
a Full Fact team of seven people
published 96 fact-checks chosen
from a queue of content provided
by Facebook algorithms.The posts they reviewed
contained potentially harmful
content, such as false statements
about vaccines, and some
had been shared more than
100,000 times.
But most of the queue provided
by Facebook contained content
that couldn’t be fact-checked,
such as statements of opinion and
random links, including a swathe
of Mr Bean videos. This highlights
the difficulty in monitoring the
more than 1 billion pieces of
content posted to the platform
each day. “Facebook’s algorithms
are not yet at a stage where theycan reliably identify information
that is inaccurate,” says Will Moy,
chief executive of Full Fact.
This is a blow for Facebook
because, alongside other
technology companies, it has said
that artificial intelligence should
be used to help tackle fake news.
But AI doesn’t seem ready yet.
Julia Bain at Facebook says
the firm’s algorithm sends content
to fact-checkers based on metrics
such as users flagging a post
and disbelief expressed in its
comments. After content is rated
as false by fact-checkers, its reach
on Facebook decreases by more
than 80 per cent, says Bain.
But Facebook hasn’t provided
Full Fact with detailed information
about the effect of their fact-
checks on reducing false content.
“We need more information to
evaluate how well the programme
is working,” says Moy.
Firms such as Snopes have quit
Facebook’s fact-checking scheme
and have similar criticisms about
the platform’s lack of transparency.
Facebook has begun providing
partners with reports on the
number of fact-checks conducted
and how often fact-checked
articles are seen, says Bain.
Moy says the partnership has
been a positive first step, echoing
the views of other fact-checkers,
but for it to have an appreciable
effect, it is necessary to
significantly step up both review
speed and content volume.
“Misinformation travels a lot
faster than the corrections do,”
says Michelle Amazeen at Boston
University. Fact-checking can be
effective but the risk is that people
may believe false content to be
true because it hasn’t yet been
labelled as debunked, she says. ❚JOEL GOODMAN/LNP/SHUTTERSTOCKFacebook is using
fact-checking firms
to combat fake news80%
Reduction in a Facebook post’s
reach, once flagged as falseThe facts about Facebook’s fact-checking The first big
report on the tech giant’s initiative to fight fake news says
there is plenty of room for improvement, finds Donna LuGeology
Michael Marshall
A VALLEY longer than the Grand
Canyon hidden under the Greenland
ice sheet may carry flowing water.
It could affect the ice sheet,
causing parts of it to move more
quickly or slowly towards the sea.
The hidden canyon was first
described in 2013 by Jonathan
Bamber at the University of
Bristol, UK. It runs for at least
750 kilometres across northern
Greenland. The Grand Canyon in
the US is just 446 kilometres long.
However, Bamber’s map of the
canyon was incomplete because it
was obtained by planes that carry
ice-penetrating radar flying in
straight lines. Bamber filled the
gaps using a statistical method
based on the average heights of
surrounding bedrock. This made
it look like the valley was blocked
at several points. But he and his
team suspected that the valley
is continuous.
Now, Christopher Chambers at
Hokkaido University in Sapporo,
Japan, and his colleagues have
developed a reconstruction of the
valley that fills in the gaps on the
basis of the canyon’s shape instead
(The Cryosphere, doi.org/c8xm).
“We get this water pathway that
links up and goes all the way
down towards the coast,” he says.
That implies there could be
a trickle of liquid water along
the canyon floor. “The base of
the ice sheet is melting very,
very slowly,” says Chambers.
The liquid water could affect
the stability of the ice sheet. If a
thin layer of water consistently
sits in the canyon, that would act
as a lubricant and allow the ice to
slide more quickly into the sea. But
a rapid flow down the canyon would
take this water away, slowing down
the ice. “It’s a potential problem for
the simulations of the ice sheets
into the future, because we need
to know where the water is going,”
says Chambers. ❚
Water may flow in
giant canyon under
Greenland ice sheet