Aggregation methods are used to aggregate attribute values into metrics displayed on components such as Chart, Pivot Table, and Results Table.
Based on its data type, each attribute can support specific aggregation methods. You can then configure attributes to only support a subset of the applicable aggregation methods. For details on the available aggregation methods, see Aggregation methods and the data types that can use them.
Each attribute also is assigned a default aggregation method. You can change the default used for each attribute.
From the attributes list on the Views page, to configure the available and default aggregation methods for an attribute: