Bias, privacy, and responsible use
AI reflects the data and choices we feed it. Here we confront bias, respect privacy, and discuss what it means to deploy AI responsibly.
Before We Begin
A facial recognition system that works well on some skin tones but fails on others. A hiring tool that penalizes resumes with women's colleges. A language model that amplifies stereotypes. These are not hypothetical—they are real headlines. This lesson examines where bias enters the ML pipeline (data collection, labeling, feature choice, evaluation), explores privacy concerns from data collection to model outputs, and discusses misuse scenarios. The goal is not to scare students away from AI but to empower them to build it better.
How this lesson fits
A model that works is not enough—it also has to be understandable, fair, and ready for the real world. This module covers the human side of AI: explaining predictions, confronting bias, and deploying models responsibly.
The big question
How do we make sure an AI system is not just accurate but also transparent, fair, and safe to deploy?
Why You Should Care
AI systems increasingly affect who gets hired, who gets a loan, who gets surveilled, and who receives medical care. Students entering this field need ethical muscle memory—the automatic habit of asking "who might this hurt?" before deploying a model.
Where this is used today
Think of it like this
Think of a mirror. A mirror does not lie, but it does not show you everything either—it reflects whatever is placed in front of it, including the flaws. AI models are mirrors of their training data. If the data carries bias, the model reflects it, often at scale. Our job is to recognize the distortion and correct it.
Easy mistake to make
Removing protected attributes like race or gender from the data does not eliminate bias. Correlated features (zip code, school name) can serve as proxies, and bias can hide in the structure of the data itself.
Think about this first
If a model is trained only on data from one city, what might go wrong when it is deployed in a different country? List as many issues as you can.
Words we will keep using
A facial recognition system that works well on some skin tones but fails on others. A hiring tool that penalizes resumes with women's colleges. A language model that amplifies stereotypes. These are not hypothetical \u2014 they are real headlines. AI reflects the data and choices we feed it, including the flaws.
Two groups with similar qualification rates apply for loans. Adjust the bias slider to introduce systematic disadvantage for Group B. Watch the fairness metrics change.
✓ Passes the 80% rule
✓ TPR is similar across groups
No bias \u2014 both groups have similar approval rates.
Approval rates should be equal across groups. Simple but may conflict with base rate differences.
Rule of thumb:
True positive AND false positive rates should be equal across groups. Stricter, more fair.
Precision should be equal across groups. The model is equally "right" for everyone.
It is mathematically impossible to satisfy all fairness criteria simultaneously when base rates differ. Choose the metric that fits your context.
Simply dropping race or gender from the data does not eliminate bias. Correlated features \u2014 zip code, school name, name spelling \u2014 act as proxies. The model can still infer the protected attribute and discriminate through the back door.
Differential privacy adds calibrated noise to data or model updates so that no single individual's data can be reverse-engineered from the output. It is the mathematical guarantee that "your participation doesn't change the result by much."
A mechanism is -differentially private if for all datasets differing in one person:
Smaller = stronger privacy = more noise = less accuracy. It's a trade-off.