> [!CAUTION] > **Caution:** This documentation is for Google Ads API **v24** . The latest active version is [**v26**](https://developers.google.com/google-ads/api/fields/latest/experiment_arm). [](https://developers.google.com/google-ads/api/fields/v24/experiment_arm_query_builder.md.txt) [](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v24/resources/experiment_arm.proto) A Google ads experiment for users to experiment changes on multiple campaigns, compare the performance, and apply the effective changes. | Attributed resources | |---| | [customer](https://developers.google.com/google-ads/api/fields/v24/customer.md.txt) | | [experiment](https://developers.google.com/google-ads/api/fields/v24/experiment.md.txt) | Fields from the above resources may be selected along with this resource in your SELECT and WHERE clauses. These fields **will not segment** metrics in your `SELECT` clause. ## experiment_arm.asset_groups.asset_group Field descriptionAsset group resource name. Category`ATTRIBUTE` Data Type`RESOURCE_NAME` Type URL`N/A` FilterableTrue SelectableFalse SortableFalse RepeatedFalse Selectable with The following fields/resources can be selected with this field: [experiment_arm](https://developers.google.com/google-ads/api/fields/v24/experiment_arm.md.txt) ## experiment_arm.asset_groups.asset_group_assets.asset Field descriptionAsset resource name of the asset group asset. Category`ATTRIBUTE` Data Type`RESOURCE_NAME` Type URL`N/A` FilterableTrue SelectableFalse SortableFalse RepeatedFalse Selectable with The following fields/resources can be selected with this field: [experiment_arm](https://developers.google.com/google-ads/api/fields/v24/experiment_arm.md.txt) ## experiment_arm.asset_testing_info.asset_variation_infos.asset_details.asset Field descriptionThe asset that is being modified for the experiment. Category`ATTRIBUTE` Data Type`RESOURCE_NAME` Type URL`N/A` FilterableTrue SelectableFalse SortableFalse RepeatedFalse Selectable with The following fields/resources can be selected with this field: [experiment_arm](https://developers.google.com/google-ads/api/fields/v24/experiment_arm.md.txt) ## experiment_arm.asset_testing_info.asset_variation_infos.base_ad Field descriptionAssociated base ad resource name. Category`ATTRIBUTE` Data Type`RESOURCE_NAME` Type URL`N/A` FilterableTrue SelectableFalse SortableFalse RepeatedFalse Selectable with The following fields/resources can be selected with this field: [experiment_arm](https://developers.google.com/google-ads/api/fields/v24/experiment_arm.md.txt) ## experiment_arm.asset_testing_info.asset_variation_infos.base_ad_group Field descriptionAssociated base AdGroup resource name. Category`ATTRIBUTE` Data Type`RESOURCE_NAME` Type URL`N/A` FilterableTrue SelectableFalse SortableFalse RepeatedFalse Selectable with The following fields/resources can be selected with this field: [experiment_arm](https://developers.google.com/google-ads/api/fields/v24/experiment_arm.md.txt) ## experiment_arm.campaigns Field descriptionList of campaigns in the trial arm. The max length is one. Category`ATTRIBUTE` Data Type`RESOURCE_NAME` Type URL`N/A` FilterableTrue SelectableTrue SortableFalse RepeatedTrue Selectable with The following fields/resources can be selected with this field: [experiment_arm](https://developers.google.com/google-ads/api/fields/v24/experiment_arm.md.txt) ## experiment_arm.control Field descriptionWhether this arm is a control arm. A control arm is the arm against which the other arms are compared. Category`ATTRIBUTE` Data Type`BOOLEAN` Type URL`N/A` FilterableTrue SelectableTrue SortableTrue RepeatedFalse Selectable with The following fields/resources can be selected with this field: [experiment_arm](https://developers.google.com/google-ads/api/fields/v24/experiment_arm.md.txt) ## experiment_arm.experiment Field descriptionImmutable. The experiment to which the ExperimentArm belongs. Category`ATTRIBUTE` Data Type`RESOURCE_NAME` Type URL`N/A` FilterableTrue SelectableTrue SortableFalse RepeatedFalse Selectable with The following fields/resources can be selected with this field: [experiment_arm](https://developers.google.com/google-ads/api/fields/v24/experiment_arm.md.txt) ## experiment_arm.in_design_campaigns Field descriptionOutput only. The in design campaigns in the treatment experiment arm. Category`ATTRIBUTE` Data Type`RESOURCE_NAME` Type URL`N/A` FilterableTrue SelectableTrue SortableFalse RepeatedTrue Selectable with The following fields/resources can be selected with this field: [experiment_arm](https://developers.google.com/google-ads/api/fields/v24/experiment_arm.md.txt) ## experiment_arm.name Field descriptionRequired. The name of the experiment arm. It must have a minimum length of 1 and maximum length of 1024. It must be unique under an experiment. Category`ATTRIBUTE` Data Type`STRING` Type URL`N/A` FilterableTrue SelectableTrue SortableTrue RepeatedFalse Selectable with The following fields/resources can be selected with this field: [experiment_arm](https://developers.google.com/google-ads/api/fields/v24/experiment_arm.md.txt) ## experiment_arm.resource_name Field descriptionImmutable. The resource name of the experiment arm. Experiment arm resource names have the form: `customers/{customer_id}/experimentArms/{TrialArm.trial_id}~{TrialArm.trial_arm_id}` Category`ATTRIBUTE` Data Type`RESOURCE_NAME` Type URL`N/A` FilterableTrue SelectableTrue SortableFalse RepeatedFalse Selectable with The following fields/resources can be selected with this field: [experiment_arm](https://developers.google.com/google-ads/api/fields/v24/experiment_arm.md.txt) ## experiment_arm.traffic_split Field descriptionTraffic split of the trial arm. The value should be between 1 and 100 and must total 100 between the two trial arms. Category`ATTRIBUTE` Data Type`INT64` Type URL`N/A` FilterableTrue SelectableTrue SortableFalse RepeatedFalse Selectable with The following fields/resources can be selected with this field: [experiment_arm](https://developers.google.com/google-ads/api/fields/v24/experiment_arm.md.txt)