AI 101

Data bias

Also known as: bias

Basics

Data bias is when the training data over-represents some groups, perspectives, or patterns โ€” and the model learns that skew, then reproduces it.

Because models compress their data, whatever’s over- or under-represented in the source gets baked in.

  • If most historical text is from one culture, the model leans that way.
  • If certain professions are stereotyped in the source, the model may echo it.

Don't blame the model alone: bias is usually a *data + objective* problem surfaced by the model. Mitigations (filtering, rebalancing, alignment) help but don't fully erase it.