Auto Research option.

[Dave]

I've never messed with this feature. How does it determine which technology select next?

[Kalemenos]

As far as I know it is random. It just picks the next technology. It may prefer a tech in the field of the researcher. I never use it until all the categories (society, physics, engineering) are all repeatable techs, so that's usually mid to late game. Then I just let it coast on auto. I just got the feeling that at that point the careful micro management didn't pay a large return on investment. Even then there may be exceptions: if I want more starbases, or higher fleet limit, etc., so I'll keep my eye on those ones.

Early game, If I'm beelining for something like synthetics or techs for ruined ring-world origin, I jot things down in ink as I play to increase my chances of getting what I want faster, and it almost always pays off. So I pay especially close attention to manage it all one by one to get to my goals, or the marginal benefits I need "right now" over the other empires like ship/weapon tech.

[Vigilante]

In my experience it just chooses the research that would be completed the quickest this will keep the exponential relatively even baring a leader with a trait for specific things sometimes shifting expected completion time … this does mean it will research things like damg for ground armies at the same rate as it would other things which means sometimes a almost useless one id chosen and it means whenever a rare appears as an option it tends to get picked if the only other option is other exponential so if you were wanting to influence the crisis by not taking jump drives or something you lose that level of control

[Ryika]

It simply reuses the AI's tech priorities, which means it prefers low tier techs and will generally mostly ignore all the good stuff in later tiers until the earlier tiers are near-empty. It'll pick up more garbage than a middle-school janitor.

The "good" way of choosing technologies is generally to do the exact opposite, and try to progress towards the higher tiers while selectively picking up the good lower level tiers.

In other words, it's terribly inefficient and you should not use it unless you really don't care about your tech efficiency. Of course it won't break your empire if you activate it, but selecting good techs just gives you so much more bang for so little attention overall.