# Enable Show Calculation Basis for Clinical Trial Study Expectedness

Learn how to configure your Vault to display whether expectedness evaluations are based on _New Info Dates_ for the _Case_ or _Onset_ dates for _Case Adverse Events_.

## About the Feature

For Clinical Trial _Study Cases_, Vault Safety now displays whether expectedness is calculated based on _New Info Dates_ or _Case Adverse Event Onset_ dates. The new _Based On_ field is available on the _Case Assessment Expectedness_ object and provides clarity on the basis for Vault expectedness auto-calculations.

After configuring this feature, for more information on the _Based On_ field, see <a href="/en/lr/01287/#expectedness-section">Case Field Reference</a>.

## Recommendation

To best use this feature, we recommend that you also enable <a href="/en/lr/737256/">Agency-Based Auto-Expectedness for Clinical Trial Study Cases</a>.

## Update the Case Assessment Layout

Complete the following steps to add the _Based On_ column to _Case Assessments_:

1. Go to **Admin > Configuration > Objects > Case Assessment > Layouts > Case Assessment Detail Page Layout**.
2. In the _Expectedness_ section, select **Edit Default Columns** and add **Based On** to the **Selected Columns** list. We recommend moving the column to below the **Expected (status)** column.
3. Select **Done**.
4. Select **Save**.