Zero-shot

Zero-shot prompting instructs a foundation model to complete a task using only the prompt itself, with no labeled examples provided. The model draws on patterns learned during pre-training to generalize to the new task. In Amazon Bedrock, any inference call without embedded examples is effectively zero-shot, making it the default starting point. The key exam distinction is between zero-shot and few-shot: few-shot prompting inserts one or more input-output examples directly in the prompt to steer the response’s format and style. Zero-shot suits straightforward, well-represented tasks but can underperform on highly specific or format-sensitive outputs where few-shot examples provide critical signal.