CustomMetricDefinition¶
Structure Class¶
dataclass
¶
The definition of a custom metric for use in an Amazon Bedrock evaluation job. A custom metric definition includes a metric name, prompt (instructions) and optionally, a rating scale. Your prompt must include a task description and input variables. The required input variables are different for model-as-a-judge and RAG evaluations.
For more information about how to define a custom metric in Amazon Bedrock, see Create a prompt for a custom metrics (LLM-as-a-judge model evaluations) and Create a prompt for a custom metrics (RAG evaluations).
Attributes¶
instance-attribute
¶
instructions: str
The prompt for a custom metric that instructs the evaluator model how to rate the model or RAG source under evaluation.
class-attribute
instance-attribute
¶
name: str = field(repr=False)
The name for a custom metric. Names must be unique in your Amazon Web Services region.
class-attribute
instance-attribute
¶
rating_scale: list[RatingScaleItem] | None = None
Defines the rating scale to be used for a custom metric. We recommend that you always define a ratings scale when creating a custom metric. If you don't define a scale, Amazon Bedrock won't be able to visually display the results of the evaluation in the console or calculate average values of numerical scores. For more information on specifying a rating scale, see Specifying an output schema (rating scale).