The hierarchy that Sarah Nexus uses to hold the model allows for varying sized and overlapping fragments to be retained when they provide information of value to the model. The method applied here is unique to Sarah Nexus.
The structural explanation for the prediction provided by Sarah Nexus is conveyed by highlighting those fragment(s) that Sarah Nexus considers meaningful. Derek Nexus also highlights fragments of the query compound in order to illustrate the matches to patterns (Markush structures) used to hold knowledge within Derek Nexus.
Both models highlight parts of the query compound for the same purpose – to draw the user’s attention to parts of the structure that influenced that prediction. How these are identified is however, very different. Derek Nexus relies on patterns drawn by experts whereas Sarah Nexus identifies those with statistical significance automatically.