A Human's Guide to Algorithmic Bias
For the past year I’ve been doing a lot of introspecting, reading, and critical thinking about bias in algorithms, particularly of the machine-learned variety. And no, I don’t mean bias in terms of the bias-variance decomposition. I mean bias in the sense that we’re all gonna be screwed if we don’t start thinking about machine learning as a tool for socioeconomic and political control.
This control can be explicit, for example in the infamous case of the COMPAS recidivism risk model, which tells decision-makers the inmates who are likely to re-offend. Or it can be subtle, like when Facebook determines what kinds of posts to show in your feed, or when Amazon recommends products for you to buy.
Applications on this spectrum of control or influence, depending on how you want to look at it, have a dark side that will bear itself out as we continue to develop machine-learning-driven tools in the context of medicine, social media, labor, education, and politics.
I’ve written about this kind of machine learning bias in the context of responsible data science, but in this post I’ll articulate a general set of questions that I hope will help you navigate the world of algorithmic applications.
Before getting into that, let’s talk about the problem.
Teaching Silicon Children
Haley Joel Osment in the 2001 film “A.I. Artificial Intelligence”
Most machine learning today comes in the form of what’s called supervised learning. You can think of supervised learning as us, the human parents, teaching our computationally gifted, silicon-based children how to recognize, process, and label patterns within a limited range of real-world phenomena. In other words, this class of algorithm learns a mapping from some input to some desired output.
Consider the following tasks:
- “Read a person’s facebook feed (
input) and tell me whether she’s likely to be a registered Republican or Democrat (
- “Given neighborhood-level drug-related arrests (
input), tell me the neighorhoods with the highest chance of drug-related crime (
- “Look at this image of a face (
input) and tell me if she’s gay or not (
output)” (btw this is a real thing).
The parent-child analogy captures the fact that these machine learning systems are still narrow in scope and cognitive ability. They might out-perform the best of us at diagnosing pneumonia, but any single machine learning system doesn’t yet possess the faculties to reason about a wider range of concerns such as thinking about the ethical implications of its own predictions.
Physiognomy, characterized by some as a pseudoscience, is “the assessment of character or personality from a person’s outer appearance, especially the face”. Source: Wikipedia.
In this sense, we can think of machine learning in the social context as a modern, more
sophisticated version of physiognomy. This is because applying machine
learning to socioeconomic and political systems is essentially the exercise of gathering
measurable characteristics about people (the
inputs) and ascribing higher-level classification
outputs) to them based on correlations between the
Kate Crawford talks about this and bias more broadly in her keynote talk at this year’s NIPS conference, but to put it briefly, the big problem arises when we start thinking more critically about classification systems and how they’re used to promulgate and solidify a particular social structure.
One notable case is that of Cesare Lombroso, a 19th century criminologist and physician. He proposed a set of physical features that characterize a “born criminal”, among them, things like large jaws, a low sloping forehead, and handle-shaped ears.
Although claims like these are problematic in themselves, the material consequences of classification systems, machine-learned or not, have to do with the actions, decisions, or policies that follow. Once we’re able to formalize and implement these classification systems in the form of machine learning algorithms, we can effectively scale out and automate the structural biases that exist in today’s society.
The “Dark Side” and the “Light Side”
The primeval struggle between good and evil, as depicted by Darth Vader and Obi Wan Kenobi
To highlight the fact that we can use the very same machine learning system for benefit or harm, let’s recast the three applications that I described above in the framework of real-world use cases.
- Read a person’s facebook feed and tell me whether she’s likely to be
a registered Republican or Democrat so that I can:
action: spread misinformation about the opposing party.
action: send them information about the relevant candidate’s platform.
- Given instances of neighborhood-level arrests, tell me
the neighorhoods with the highest chance of future crime so that
action: implement a stop-and-frisk policy and increase police presence in those areas.
action: increase funding and support for employment-based recidivism prevention programs.
- Look at this image of a face and tell me if he’s gay or not so that I can:
action: identify likely candidates to send to “conversion therapy”.
action: send him relevant information about sexual health.
Notice that the differences in
actions in each application can be subtle,
and our value judgement about “rightness” or “wrongness” depend on our own
belief systems and how exactly actions, decisions, and policies are
Quite honestly, the “dark side” and “light side” is itself a simple binary classification system that is often too simplistic to apply to real-world situations. So, as any experienced ethicist can tell you, I think the best we can do is to continue to ask the right questions, come up with a necessarily incomplete but constantly evolving set of answers, and try to act accordingly.
Question the System
The next time you’re using Facebook, Amazon, Netflix, or any other digital product, and it serves you some sort of prediction about what content you might enjoy, what thing you might want to buy, or who you might want to connect with, ask yourself:
- What historical training data did the app use to make this prediction?
- Are these data correlated with socially sensitive attributes like race?
- What do the architects of this system have to gain in making this prediction?
- Are any socially sensitive attributes correlated with the labels?
- Who labelled the training data, and who decided what the labels are to begin with?
- What kinds of characteristics about me does the system know about?
- Is the system making this prediction because I belong to a particular social group?
- Is the classification system underlying the predicted labels realistic?
- How are my actions on this app being fed back into the machine learning algorithm?
- How are the predictions influencing my own view of the world?
Think of these as a sort of mental vaccine to immunize yourself from taking for granted the fact that these useful and convenient services aren’t just here to make your life better. It’s all too easy to forget that these apps reflect the hopes, desires, and biases of its architects, who happen to be human beings too, at least for now…