It was thought that one way of finding information is to ask your network (Facebook and Twitter would be examples), and then they would pass on the message and a chain of trusted sources would get the information back to you.
I am being purposefully vague because I don't think people know what an effective version of that would look like, but its worth exploring.
If you have some data you might ask questions like:
1. Can this network reveal obscure information?
2. When -- if ever -- is it more effective than indexing by words?
This seems significantly laborious. Not sure that the utility of this kind of network recommendation scales to incentivise participation beyond a few people. i.e.: We already have user groups on sites like reddit, FB etc, where experts or enthusiasts answer questions when they feel like it. But this is a slow process that relies on a group that contains enough distributed knowledge, but isn't overwhelmed with inquiries. As a counter example, the /r/BuildaPC subreddit long ago exceeded the size where it could answer a significant proportion of build questions, and most remain unanswered despite significant community engagement.
Not convinced any kind of formalised 'question answering network' could replace search. It would be both slow, and require an enormous asymmetric investment of time, for a diffuse and unspecified reward.
Suppose you like fountain pens, and you recommend certain ones. One of your friend looks for fountain pens that their friends recommend and finds the ones you like.
That is just one example of things that don't require explicit questions.
Another one might be you have searched for books or other things and then they follow the same "path". So long as you have similar interests it might work.
People haven't solved this issue, but there is a lot of research out there on networks of connections potentially replacing certain kinds of search.
I am being purposefully vague because I don't think people know what an effective version of that would look like, but its worth exploring.
If you have some data you might ask questions like:
1. Can this network reveal obscure information?
2. When -- if ever -- is it more effective than indexing by words?