In v4.44 we have made improvements to the evidence for a Rainbird result.

The evidence API endpoint has been updated to return additional information that provides increased explainability of a generated fact.

This includes:

  1. the maximum certainty the rule was allowed to produce
    1. This is configured by the author within the Studio, often to express that a fact can be generated with lower certainty in the event there’s less data to make an inference. In this scenario a fact could be created where all the conditions of the rule have been met with 100% certainty, but the resulting fact only has 50% certainty. The maximum rule certainty provides an explanation for this scenario.
  2. the % impact of each condition to the certainty of a fact
    1. The certainty and weight of each condition has a bearing on how much impact it has on the certainty of a fact. This has been available in our evidence application, when viewing the details of a rule, but it is now available from our API for customers to use this data directly.

The evidence application has also been updated with this new information.

When viewing the details of a rule (clicking the box highlighted), the maximum certainty will be displayed if it was lower than 100%.


The impact calculation has also been updated to take into account the maximum rule certainty. With this additional context it ensures the impact percentage is based on the maximum that was allowed, rather than always assuming that 100% was the maximum possible. The total of all impact percentages will now always equal the certainty in all scenarios.

These changes will only apply to the evidence of queries using v4.44 or above. The evidence for queries made using v4.43 and earlier will remain unchanged and so will not return maximum rule certainty or impact % via the API and the Evidence application will display the impact using the old calculation.

v4.44 is available in Community now (11th September 2023) and will be deployed to our Enterprise platform on Monday 18th September at 5pm

If you have any questions about this change, please feel free to comment or email us on

The Product Team