Prompt drift
Prompt drift is the gradual loss of adherence to a prompt’s instructions over a long conversation, as earlier instructions are outweighed by more recent turns.
Drift is why a persona slips after twenty exchanges and why formatting rules stop being followed. Restating the key constraints periodically, or moving them into a system prompt, holds them in place.
Related terms
- Recency bias
- Recency bias is a model’s tendency to give more weight to instructions near the end of a prompt than to those buried earlier.
- System prompt
- A system prompt is a persistent instruction that sets a model’s role, rules, and boundaries for an entire conversation, separate from the individual messages a user sends.
- Context window
- A context window is the maximum amount of text, measured in tokens, that a model can consider at once — including the prompt, any supplied documents, and the reply it generates.
More on failure modes
See the full glossary, read the guides, or put it into practice in the prompt builder.