Model Drift
When a model gets worse over time because the world moved on and it did not. A pricing or demand model trained two years ago quietly stops matching how customers behave now.
Related terms
Training Data
The text, images or code a model learned from. It shapes everything the model knows and every bias it carries, and it is why what your website said two years ago may still be what an assistant repeats.
AI Policy Page
A public page stating how a business uses AI and what it does with customer data. Increasingly expected, and cheap to write honestly.
PerplexityBot
Perplexity’s crawler. Perplexity cites its sources prominently, so being readable by it is one of the more direct routes to a visible citation.
Inference
The moment an AI actually answers, as opposed to when it was trained. Training happens once and costs a fortune; inference happens every time somebody asks, and is what you pay for per use.
Prompt Engineering
The craft of writing instructions that get reliable results from an AI — being specific, giving examples, saying what to avoid. Less mysterious than it sounds, and mostly the same skill as briefing a new colleague well.
Reinforcement Learning
Training by trial, error and reward rather than by examples. It is how models are tuned to be helpful and to refuse things they should refuse.