# ExpressionKind

Canonical page: https://www.adaptabletools.com/docs/reference/expressionkind

Evaluation strategy of an AdapTableQL Expression, inferred from its text:

- `scalar` — evaluated per row (e.g. `[price] > 100`, `[qty] * [price]`)
- `aggregated` — evaluated over a set of rows (e.g. `SUM{[notional]} > 1000000`,
 `AVG{[price], GROUP_BY([sector])}`)

Live (observable) functions (`CHANGE_COUNT{[price], WITHIN(5m)} >= 3`,
`ROW_AGE{}`) read the row's own change history and are `scalar`.

Kind is a property of the syntax: `NAME(...)` is a per-row function call,
`NAME{...}` is a set call. State objects therefore store expressions as
plain strings and AdapTable infers the kind.

```ts title="TypeScript"
export type ExpressionKind = 'scalar' | 'aggregated';
```