---
title: "EvaluationError.duplicateMetricName(name:)"
framework: Evaluations
role: symbol
role_heading: Case
platforms: [iOS 27.0+, iPadOS 27.0+, Mac Catalyst 27.0+, macOS 27.0+, visionOS 27.0+, watchOS 27.0+, xcode 27.0+]
path: "evaluations/evaluationerror/duplicatemetricname(name:)"
---

# EvaluationError.duplicateMetricName(name:)

Two evaluators — or a single evaluator returning multiple metrics — produced a metric with the same name for the same sample.

## Declaration

```swift
case duplicateMetricName(name: String)
```

## Parameters

- `name`: The metric name that was produced more than once.

## Discussion

Discussion Metric names double as DataFrame column names, so a repeated name would otherwise silently overwrite the first metric’s value instead of failing loudly.