Simple algorithm deduces political opinion from tweets

It is legal for a twitter user to be categorized by political views, and used for demographic purposes. This is made possible by a program based on a simple algorithm. But this algorithm can also be misleading.

Hernani Marques does not make a big fuss about his self-made program. "I did it in a night and fog operation", says the "hacktivist" of the Chaos Computer Club Switzerland in an interview with the news agency Keystone-SDA. The tool is "very primitive and simple", but can be expanded at will.

Specifically, the program compares the language usage of any Twitter user with the language usage of the various Swiss and some German parties. The tool compares which party's website most closely matches their own writing style on Twitter.

Marques downloaded the parties' websites on a key date in October 2018. If the software finds the same words or phrases in a user's tweets as a party's, it generates a hit. The more hits, the higher the bar of the corresponding party.

Recognize changeover selector "I'll use your tweets to show you what your political opinion is," says Marques. This is done legally. Twitter has an open interface and allows anyone with even a modest knowledge of IT to download and use various data. "The program and how it works does not violate any applicable law in any way".

The problem: Users are unaware they are being drafted, and perhaps even more disturbing, the result can be wrong. "Whether it's true or not doesn't matter," says Marques. "The algorithms have spoken. Even cautious Twitter users who strive for a neutral political tone are put in a drawer.”

The data is useful for parties, for example. They could send targeted advertisements or messages to users of social networks who are in a similar political spectrum but still voted for the competition in the last elections. "Working towards citizens moving in the right direction," Marques describes it.

Adjust target group His tool is like other programs of the Chaos Computer Club not for sale. Together with his colleagues, they call themselves "hacktivists", he draws attention to opportunities, but also to risks and dangers in digital space, without commercial intentions.

According to Marques, however, his program could simply be further developed by professional IT providers - a lot could be achieved with relatively few resources. "If a party takes 100,000 francs into its hands, there's a lot more that can be done.

In addition, various players could buy additional user data not intended for the public, such as private messages from professional hackers. This could refine the algorithm. Parties could win over potential voters in an even more targeted way, without their knowledge.

This blog was translated form following article: https://www.werbewoche.ch/digital/2019-03-03/einfacher-algorithmus-schliesst-von-tweets-auf-politische-gesinnung

Photo by Markus Spiske on Unsplash