Evaluation Metric Failure
Observations report the value of your metric evaluated on a given set of assignments. Sometimes, though, a set of Assignments is not feasible for evaluation. For example, a machine runs out of memory, a chemical mixture fails to stabilize and is not measurable, or the Assignments are simply not in the domain of the function you're trying to optimize.
Learning Failure Regions
As you report more of these failed Observations, our internal machine learning algorithms will figure out the feasible region and only recommend points there, optimizing your Experiment within this restricted, non-rectangular domain.
Note: The complexity of the failure region and the tightness of your Parameter Bounds impact the speed at which we will learn an Experiment's failure region.