The article combines two theories, Nash implementation and Bayesian implementation, into one framework. It looks at situations where each person has private information and a known type, but the designer doesn't know these details. The study identifies conditions that fully describe when a social choice can be implemented in economic environments. In non-economic settings, there is still a gap between what is needed and what is enough, but the researchers introduce a stronger condition called essential-generalized-Bayesian monotonicity to help bridge this gap.