Pavonis Interactive Forums

You get +1% on alien research every time a councilor investigates an Alien Activity (crashed UFO, shimmery abduction site). But this bonus maxes out at +50%. At that point, is there any reason to continue investigating these site?

Can't say for sure.

But you always have a chance to reveal an alien, and you might still need to do the kill or capture objective. Or reveal an alien structure, which is a good place to get salvage components.