Regarding "which best describes how you validated your original business idea?", is anyone aware of more research around the effectiveness or practicality of different validation approaches? That is, rough false-positive (validation indicated that business idea had sufficient market demand when it didn't) and false-negative rates (validation indicated that business idea had insufficient market demand when it did) for different validation approaches.

Naively it'd be great to have data of the form "given our idea for a business was bad specifically because there would be insufficient market demand, when we validated the idea by method A (e.g. getting verbal commitment from n potential customers), validation result indicated there was enough market demand to proceed, we decided to proceed, but the business failed later specifically for a reason that the validation approach was intended to measure (customers willing to buy the service) and not for some other reason". I.e. known ground-truth, measurement, measurement result, decision to proceed or abort based on measurement result, actual outcome.

Probably would be a very tricky thing to isolate the effectiveness of the validation approach and tease it apart from other confounding factors.