---
title: "Effect"
description: "the change where it ran against the change where it did not, with an interval; or withheld with what would settle it"
section: concepts
address: /concepts/effect
contract: 0476e35e6e275db5
---

# Effect

the change where it ran against the change where it did not, with an interval; or withheld with what would settle it

[figure: Effect is a fact at strategy scope. The drawing shows its fields and the objects that they point at.]

| property | value |
|---|---|
| kind | fact |
| scope | strategy |
| key | the move and the window |
| store | postgres+lake |
| family | strategy |



## Fields


| field | type | required | note |
|---|---|---|---|
| `move` | `id` | yes |  |
| `design` | [DesignOfAnEffect](/concepts/designofaneffect) | yes | the design that read it, fixed before the window opened |
| `change` | [Interval](/concepts/interval) | no |  |
| `holdout_change` | [Interval](/concepts/interval) | no |  |
| `effect` | [Interval](/concepts/interval) | no |  |
| `floor` | `share` | yes |  |
| `withheld` | `bool` | yes |  |
| `what_would_settle_it` | `text` | no |  |
| `forecast` | `id` | yes |  |
| `assignments` | `[id]` | yes |  |
| `read_at` | `time` | yes |  |
| `verdict` | `one of held \| missed \| cannot tell` | no | the forecast's verdict: held when the effect's lower bound clears the number that proves it wrong, missed when its upper bound does not, cannot tell between |
| `share_above_zero` | `share` | no | the share of the effect's interval that lies above zero; absent when the effect is withheld |
| `cause_claimed` | `bool` | yes | true when the share above zero reaches the bar of the row that names the share below which no cause is claimed, so the impact is raised; false leaves the effect measured and raises no impact |



## Routes that use it
- [`/v1/read/effect`](/reference/read/effect) returns it