Simple algorithm infers political sentiment from tweets
By legal means, any Twitter user can now be pigeonholed politically and, for example, can be specifically courted by political parties. This is made possible by a program that is based on a simple algorithm. But this algorithm can also be wrong.
Hernani Marques does not make a big fuss about his self-made program. "I made it in a night and fog operation," says the "hacktivist" of the Chaos Computer Club Switzerland in an interview with the Keystone-SDA news agency. The tool is "very primitive and simple", but can be expanded at will.
Specifically, the program compares the language use of any Twitter user with the language use of the various Swiss and some German parties. The tool compares which party website one's own writing style on Twitter most closely matches.
To do this, Marques downloaded the parties' websites on a key date in October 2018. If the software finds words or phrases in a user's tweets that are identical to those of a party, it generates a hit. The more hits, the higher the swing of the corresponding party's bar.
"I show you what your political views are based on your tweets," Marques says. This is done legally, he adds. Twitter has an open interface, he says, and allows anyone with even modest IT skills to pull and use various data. "The program and how it works does not violate any applicable law in any way."
The problem: No user notices that he is being pigeonholed. And - perhaps even more disturbing: the result can be wrong. "Whether it's true or not doesn't matter," Marques says. "The algorithms have spoken." Even careful Twitter users who strive for a neutral political tone are pigeonholed.
This data could be useful for political parties, for example. They could send targeted advertising or messages to users of social networks who are in a similar political spectrum but voted for the competition in the last elections. "Working to get citizens to move in the right direction," is how Marques describes it.
Like other programs of the Chaos Computer Club, his tool is not intended for sale. Together with his colleagues - they call themselves "hacktivists" - he draws attention to opportunities, but also to risks and dangers in the digital space, without commercial intentions.
According to Marques, however, his program could easily be developed further by professional IT providers - a lot could be achieved with relatively few resources. "If a party invests 100,000 francs, then a lot more can be achieved.
In addition, various actors could purchase further user data not intended for the public, such as private messages from professional hackers. This could refine the algorithm. Parties could win over potential swing voters in an even more targeted manner - without their knowledge. (Sebastian Gänger, Stefan Lanz, Keystone-SDA)
