EVALUATOR Spans
Purpose
EVALUATOR spans represent quality assessment operations (answer relevance, faithfulness, hallucination detection).
Required Attributes
| Attribute |
Type |
Description |
Required |
openinference.span.kind |
String |
Must be "EVALUATOR" |
Yes |
Common Attributes
| Attribute |
Type |
Description |
input.value |
String |
Content being evaluated |
output.value |
String |
Evaluation result (score, label, explanation) |
metadata.evaluator_name |
String |
Evaluator identifier |
metadata.score |
Float |
Numeric score (0-1) |
metadata.label |
String |
Categorical label (relevant/irrelevant) |
Example: Answer Relevance
{
"openinference.span.kind": "EVALUATOR",
"input.value": "{\"question\": \"What is the capital of France?\", \"answer\": \"The capital of France is Paris.\"}",
"input.mime_type": "application/json",
"output.value": "0.95",
"metadata.evaluator_name": "answer_relevance",
"metadata.score": 0.95,
"metadata.label": "relevant",
"metadata.explanation": "Answer directly addresses the question with correct information"
}
Example: Faithfulness Check
{
"openinference.span.kind": "EVALUATOR",
"input.value": "{\"context\": \"Paris is in France.\", \"answer\": \"Paris is the capital of France.\"}",
"input.mime_type": "application/json",
"output.value": "0.5",
"metadata.evaluator_name": "faithfulness",
"metadata.score": 0.5,
"metadata.label": "partially_faithful",
"metadata.explanation": "Answer makes unsupported claim about Paris being the capital"
}