# Aggregation

Learn how to aggregate data in Altair.

## We'll cover the following

**Aggregation** involves summarizing data using a specific calculation, such as mean, median, sum, count, etc. Altair provides several built-in aggregation functions, including `count`

, `sum`

, `mean`

, `median`

, `min`

, `max`

, and `stddev`

.

## How to aggregate values in Altair

Altair provides the following two ways to aggregate values:

At the encoding level, we use the

`aggregate`

function directly in the field to aggregate. We use the competition dataset.

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