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Bias and discrimination in machine learning

Imagine a group of government officials who take and process passport applications. The application consists of filling in a form and handing over one photo of the applicant’s face. All officials try to do good work except one. That official is racist and rejects every application from a person who looks different. The people in the government notice the discrimination. They decide to introduce a machine that will learn from all applications processed by good officials. The machine is consistent; it equalizes criteria for all applications, so current and future discrimination is gone. But is it?

At first glance, everything works fine. However, over time the people at the government get many complaints from people of Asian descent: photos with distinctly Asian facial features usually don’t pass automated checks. How is that possible? Shouldn’t the machine be consistent?

The example above is not imaginary; it’s based on real-world situations. A man’s visa application was rejected in New Zealand because the machine thought his eyes were closed on his photo. A face-detection software in cameras asks if someone is blinking if the camera is pointed toward a person of Asian descent. This can happen to any type of face. An MIT grad student found that a publicly available software for face detection didn’t recognize faces with dark skin tones at all.

Let’s acknowledge that many such outcomes are not intentional. The underlying problem is that a machine learned from incomplete data: photos of people of Asian descent or with dark skin were not used as learning examples. The machine learned that the whole population consists only of people with fair skin, and held an implicit bias against those who were not in that population.

The fix for this, and for the more general problem of bias and discrimination in machine learning, is hard for many reasons:

  • People don’t realize they aren’t inclusive. It’s easy to recognize a movie star in the latest blockbuster. In contrast, it’s hard to notice that a small-time actor, who played in a couple of movies ten years ago, didn’t make a movie since then. Likewise, it’s easier to notice an error in training examples you have than to notice that some examples are missing.
  • Having many good and diverse examples needed for machine learning is rare. Bigger companies and institutions might have them, but the examples are usually not shared for business or privacy reasons (think medical records).
  • Companies operate in a system that favors firstcomers so they’re often incentivized to release early. Some of them rush and don’t think through all the consequences their machine learning models might have.

When I had an issue at a counter in Croatia, I would go to another one or come back later; the issue would go away because a different person would be sitting there. However, what if there is only one machine behind every counter at all times? Or at border crossings? Or in hospitals and schools? We have to fix the problem of bias in machine learning because the alternative is not an option.

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