# get\_properties

### Description

`get_properties_from_instances` or `get_properties` extracts the values for a specified property or field from all [instances](https://docs.atfinity.io/guides/glossary/instance) of specified [ontologies](https://docs.atfinity.io/guides/glossary/ontology).

The first argument is always the call of instances. The resulting values are returned as a list and can be passed to different functions, for example [`SUM`](https://docs.atfinity.io/rule-language/operators/mathematical-operators/sum), [`AVG`](https://docs.atfinity.io/rule-language/operators/mathematical-operators/avg), or [`COUNT`](https://docs.atfinity.io/rule-language/operators/list-operators/count).<br>

### Example

```
AVG(
    get_properties(
        instances(AccountHolder), risk_level
    )
)
```

Here, the average risk level over all account holders is calculated. Replace the operator `AVG` with, for example, `MAX` if you are looking for the highest risk level for an account holder. Replace the parameter `risk_level` with `aum` if you want to know the average value of assets under management for your account holders. Don't forget the single quotation marks around the parameter.

You can also use the operator `get_properties_from_instances` in a boolean expression, if, for example, you want to trigger something when the average overall risk level raises above 3.

Simply add the comparison, e.g. `> 3` at the end:

```
AVG(
    get_properties(
        instances(AccountHolder), risk_level
    )
) > 3
```