If you have a Nodebb instance and want World posts to include a certain topic, lets say on electric cars.
If you follow people that are into electric cars then that happens.

(1) I cant seem to search on a topic in nodebb World.
So the way Ive been expanding the World, is by going to mastodon, searching topic, either by tag or by name. Then if I see an interesting profile, I reply to one of their posts with cc'ing in my nodebb account.
Then their post comes up in World on nodebb, and I can follow the author.
Hence this is a lot of moving around to follow people who are into a certain topic.

Is there a faster way? E.g. is there a method to type a topic in nodebb World, and see relevant posts or people there, and follow them immediately?

(2) When I follow someone from a Mastodon site, I seem to be following a clone of their account. I.e. account created 8 Nov 2022, 00:00, 1 post.
Not their mastodon profile with many posts and followers

@eeeee the way ActivityPub works is as you surmised, via follow relationships. I detail that bit here in the documentation, which I think you've read.

So the way Ive been expanding the World, is by going to mastodon, searching topic, either by tag or by name. Then if I see an interesting profile, I reply to one of their posts with cc'ing in my nodebb account.
Then their post comes up in World on nodebb, and I can follow the author.

To shortcut this, you can search either the author (@handle@domain) or post URL in NodeBB. From there, NodeBB will attempt to pull that content in via ActivityPub, so you don't need to reply to them.

Is there a faster way? E.g. is there a method to type a topic in nodebb World, and see relevant posts or people there, and follow them immediately?

Unfortunately not, since ActivityPub isn't built in a centralized way that allows for something like this. I face similar issues with the OpenBeta community. The rock climbing community is around on fedi, but finding them is tough. I do as you do, I follow people who post about climbing related content and over time my /world tends to populate with their content automatically.

What I also do on my site is follow a hashtag. In my case, #climbing. When followed, any new topics that are posted with that hashtag notify you, so you can move them out of world, etc.

Lemmy communities are also great to follow, because they automatically boost everything that happens in their community, so you can get access to everything that happens in that lemmy community automatically. (e.g. I follow @startrek@startrek.website here, and their posts show up in world automatically).

Lastly, I also follow a newsmast channel, @sport@newsmast.community, which also boosts a ton of related content. There is probably one for technology.

@eeeee said in Efficient way to increase World posts on a topic?:

(2) When I follow someone from a Mastodon site, I seem to be following a clone of their account. I.e. account created 8 Nov 2022, 00:00, 1 post.
Not their mastodon profile with many posts and followers

When you query a remote user, they are given a local representation in NodeBB. The creation date is different because it cannot always be trusted. If a remote user reports their creation date as 1 Jan 2588, I don't think that would be correct... but it is allowed in ActivityPub to do that :rofl: — so I just use the date they were first queried.