Sayid is tested/tortured by Dogen with ash, electric shock & hot poker

In Dogen's office area, Sayid is strapped to a table. Dogen proceeds with his testing.

First, he throws what appears to be the same ash used to guard against the smoke monster on Sayid. Dogen watches closely as the ash falls onto Sayid's body.

Next Dogen attaches electrodes to Sayid, then turns a crank which and then a dial which sends electricity through Sayid's body. Dogen looks at Sayid and then looks back at the machine.

Last, Dogen takes a hot metal poker and lays it on Sayid's skin, causing him to scream in agony. Dogen leans over and looks very closely at Sayid's face while he burns him.

Lennon comes over to let Sayid out and apologizes for having to put him through that. He says it was a test that he passed. Once Sayid is gone Lennon says "I just lied to him, didn't I?" Dogen confirms that.

So what exactly were these tests supposed to prove and what about Sayid's reactions to them leads Dogen to believe that he failed?