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
Agentic Browsing
An AI navigating a website on somebody’s behalf: finding the price, checking availability, sometimes buying. Sites that rely on hover menus and unlabelled buttons are hard for an agent to use.
Markdown
A plain-text way of writing formatted documents using symbols like # for a heading. AI systems read it easily because the structure is unambiguous, which is why some sites now offer it alongside HTML.
Sentiment Analysis
Automatically judging whether text is positive, negative or neutral. Used to read reviews and messages at a scale nobody could read by hand.
Content Provenance
A record of where a piece of content came from and how it was made, sometimes attached to the file itself. Emerging as a way to tell an original photograph from a generated one.
Semantic Search
Search that works on meaning rather than exact words, so a page can match a query it never literally contains. It is why writing naturally now beats repeating a keyword.
Answer Engine
An answer engine replies to a question with a written answer instead of a list of links. ChatGPT, Perplexity and Google’s AI Overviews are all answer engines. The old question was “do we rank?”; the new one is “are we the answer?”