Data Gathering resources can be retrieved via the Get DataGathering endpoint of the Janus API. The response of this request will contain the Observation Item Sets required for the evaluation step. It is recommended to use Events as the trigger to fetch these results.

There are several reasons a Data Gathering may be unable to be evaluated:

1. The assessment has been canceled or expired using the Patch DataGathering endpoint. This will prevent the user from completing the assessment, and the DataGathererComplete event will never be sent. Results for a canceled or expired assessment cannot be retrieved, as the assessment is still incomplete.
2. The assessment has been terminated due to measure-specific conditions being met. This only applies to certain measures where it's possible for the assessment to become impossible to complete, for example due to a timeout. In these cases, the DataGathererComplete event will be sent as normal, but the "resourceSubState" in the retrieved results will contain "Terminated" or "Timedout" instead of "Successful". In a terminated assessment, the user's inputs are available to view, but it's unlikely that the results can be scored successfully (dependent on the measure).