Who needs the reasoning, and why
Chemist
- Needs to know which feature to change next
- A bare score ranks but does not guide design
Reviewer or regulator
- Needs a basis that can be checked and challenged
- An unexplainable input is hard to admit into a consequential decision
Clinician or patient
- Needs to know why this compound, for this person
- Opacity that is inconvenient in research becomes an obstacle to care
Interpretability and accuracy often pull against each other. A simpler model that can be explained may predict less well; a more accurate model may be opaque. There is no universal right answer — the acceptable balance depends on what the prediction will be used for.