What methods do you use to research and evaluate whether there is already a demand for a service that uses AI or ethical ways of using AI to provide services through SaaS products?
You can conduct some customer interviews. But just doing cursory research on various social media platforms also helps.
I wrote something on it too:
https://www.indiehackers.com/product/evoke/how-i-got-customer-interviews-to-validate-my-product-with-just-an-idea--NIFTGfXDAwyrx4_DUsP
You can also follow me on twitter to see more: https://twitter.com/TheRealEtch
And it really depends on your business. If you're comfortable sharing, I'd need to hear more details before I can make any suggestions.
Build an MVP :)