Discovery Needs More Than Yes or No

Many discovery agents test one hypothesis against its negation, so a failed hypothesis says little about which alternative should replace it. Contrastive Discovery instead asks the agent to maintain a mutually exclusive, collectively exhaustive set of explanations and score each experiment by how it moves belief across that set. Across six domains, the authors report that contrast sets resolved 73% of high-shift cases that pointwise evaluation merely rejected; when the sets guided search, the agent resolved 67% more questions under the same experiment budget. In a blinded study, 38 human experts chose the same explanation on 78% of resolved questions, evidence for the method within the evaluated tasks rather than proof of autonomous scientific discovery.