---
title: AggregationOperation
framework: evaluations
role: symbol
role_heading: Enumeration
path: evaluations/aggregationoperation
---

# AggregationOperation

The type of aggregation operation used to compute a summary statistic.

## Declaration

```swift
enum AggregationOperation
```

## Overview

Overview Each case pairs a statistical function with the Metric it operates on, except AggregationOperation.custom(label:) which represents a custom computation.

## Topics

### Enumeration Cases

- [AggregationOperation.custom(label:)](evaluations/aggregationoperation/custom(label:).md)
- [AggregationOperation.maximum(of:)](evaluations/aggregationoperation/maximum(of:).md)
- [AggregationOperation.mean(of:)](evaluations/aggregationoperation/mean(of:).md)
- [AggregationOperation.median(of:)](evaluations/aggregationoperation/median(of:).md)
- [AggregationOperation.minimum(of:)](evaluations/aggregationoperation/minimum(of:).md)
- [AggregationOperation.mode(of:)](evaluations/aggregationoperation/mode(of:).md)
- [AggregationOperation.standardDeviation(of:)](evaluations/aggregationoperation/standarddeviation(of:).md)
- [AggregationOperation.variance(of:)](evaluations/aggregationoperation/variance(of:).md)

### Instance Properties

- [label](evaluations/aggregationoperation/label.md)

### Default Implementations

- [Decodable Implementations](evaluations/aggregationoperation/decodable-implementations.md)
- [Encodable Implementations](evaluations/aggregationoperation/encodable-implementations.md)

## Relationships

### Conforms To

- [Copyable](swift/copyable.md)
- [Decodable](swift/decodable.md)
- [Encodable](swift/encodable.md)
- [Equatable](swift/equatable.md)
- [Escapable](swift/escapable.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Inspecting aggregate results

- [AggregateMetric](evaluations/aggregatemetric.md)