---
title: Create a decision dataset in Analytics
slug: web-experimentation/docs/create-a-decision-dataset-in-analytics
docTags: 
createdAt: 2026-07-20T15:45:19.533Z
---

Decision events (or impressions) are special events triggered when Optimizely Experimentation "decides" that a visitor is bucketed into a certain experiment and variation pair. See [Data specification](docId:4-lPKAXtBWlId5sZkefgn) for information.

Create a decision dataset to integrate your Experimentation data. This helps you centralize and analyze your experiment results along with additional information in your data warehouse. 

1. Go to **Data >** **Datasets >** **+ New Dataset >** **Source Dataset**.

   ![opti-decision-dataset.png](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/MFWEFPPqIsFYHXfrRNk1T-20260720-145759.png)
2. Select your data from the connection you previously configured in the [Create a connection](docId\:ZT4ZItwyGX5hEnl0fgOMK) section on the **Pick a Source** page and click **Confirm**. Use the search box to find your tables in the warehouse. 

   ![search-tables-new.png](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/WVFfHSEY2kFozwbddgAQi-20260720-145759.png)
3. Give your dataset a name and click **Save**.

   ![save-dataset.png](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/5Q1ZaVYaPzjeEU4a4MNNH-20260720-145759.png)
4. Select **Decision Stream** from the drop-down list in the **Semantics** tab.

   ![opti-decisiondataset-3.png](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/gpkvETXvpRspN_hSs3W8i-20260720-145759.png)
5. Complete the **Decision** configuration by configuring the following fields:
   - **Actor dataset** – The actor corresponding to the identifier used for experiment variation decisions, which is typically a user. The decision dataset and the event dataset must have a many-to-one relationship with this actor dataset.
   - **Experiment ID** – The experiment ID used by Optimizely. ID is preferred, but if it is not available, leave it blank and populate the experiment name or the rule key. 
   - **Rule key** – The rule key assigned by Optimizely to identify experiments. This is required only if the Experiment ID is not available.
   - **Experiment name** – The experiment name used by Optimizely. This is required only if the Experiment ID and the rule key are not available.
   - **Variation** – The variation ID used by Optimizely. The variation ID is preferred, but if it is unavailable, you can select the variation name or variation key as an alternative.
   - **Timestamp** – The time at which the decision was made.
   - **Is holdback (optional)** – The boolean column that indicates decisions that should be excluded from the experiment.
   - **Custom partition time column (optional)** – The option you use when the decision table is partitioned by a timestamp or date column other than the decision timestamp specified. When specified, each query on the decision dataset includes a filter on the custom partition time column in addition to the decision timestamp column. The **before** and **after** skew settings let the filter on the custom partition time column to be wider than the time range selected by the user. For example, with the default settings of *1 day* before and after, a user-specified time range of *November 10 to 15* would be expanded to *November 9 to 16*.

     ![opti-decisiondataset-4.png](https://api.archbee.com/api/optimize/BrbvVORKJ5iIeSMZye5kI/XxARqs4Adg13G5ZbWUdmo-20260720-145759.png)

:::hint{type="info"}
**Note**

If you use external decision datasets to [analyze non-Optimizely experiments](docId:9u2ofGBUaZOpdQXaTeZ0n), the experiment ID, variation ID, user ID, and timestamp are mandatory.
:::

See [Create new datasets](docId\:ceeHwVegmTgp3ZecBx86k) for information.