Dude, what ARE they like? Do they have you make a ball float or something or do they tell you that Lofwyr wants you dead and see if the fear makes you Awaken?

Give the potential a few doses of that drug that makes any awakened person astrally percieve, and see if the watchers can punch him.

It probably is mostly interviews to begin with. Since most of these would be regarding children, it would probably consist of questions to the parents about strange things happening, did the child have an imaginary friend that was more real than it aught to be? Did the child ever get scared or angry and cause harm to someone or some thing at a distance? Are they better at sports than other kids? Can they run fast, react in the blink of an eye or really knock the snot out of the other kids at Tae Kwan Do practice? Or are they really quiet, able to sneak up on cats and always win at hide and go seek?

After that,they would probably have a mage very skilled in Assensing have a close look. That mage would study the child's aura in great detail looking for the least sing of the Talent. If they find it, I suppose the other tests would depend on what they find and what the interviews turned up. Potential adepts might get a lot of physical tests while a potential mage would get, well that's a tougher question. Maybe they would be put in situations like those the interviews revealed caused them to manifest their powers. Or more likely they would be taken to kind of a kintergarten for mages where they learn the basics of their power and specially trained mundanes and mages work with them to bring out that power, if any.

That's probably how it would work in the corporate world. Street kids would be lucky to find a mentor that noticed them and took them under their wing. Failing that, they might never really learn about their power and how to use it. Shaman would have it easier though since their Totem would help them out some.

Kids outside of the corps but in the school system would have a chance of getting noticed, just how likely depends on the school system in question and how powerful the kid is and luck. The kid would probably get recruitment offers from the corps once they learned the kid had Talent, which would lead down the road of corp wageslavedom. They might also turn those offers down and take a tutor or go to a private (or is it?) school for mages.

The way Street Magic makes it sound they got corporate headhunters out everywhere looking for talent. Regardless, I have no idea how they would screen for it. Wouldn't a mage assensing work, or does it have to be a fully awakened talent for a mage to be able to tell if someones awakened?