In Philip K. Dick's "Do Androids Dream of Electric Sheep?", this is the test that is used to distingush between androids and humans. A flat adhesive disk is attached to the cheek to measure the "blush" reaction. At the same time fluctuations in the tensions in the eye muscles are measured by way of a pencil-beam of light. Reaction time is a factor.
The examiner asks questions about social situations, and the subject then expresses their reaction. The actual answers given are not important - instead the involuntary muscular response is measured. The theory behind the test is that androids do not share the human trait of empathy, and so do not react as strongly or as quickly, if at all.

In way of example, a sample of the questions administered by Rick Deckard during the course of the story:
"You're sitting watching TV, and suddenly discover a wasp crawling on your arm. What do you do?"
Or, my favorite: "You are watching an old movie on TV. It shows a banquet in progress; the guests are enjoying raw oysters. The entree consists of boiled dog, stuffed with rice. Are raw oysters more acceptable to you than boiled dog?"

Typically, you would expect an android to react clinically to the situation (For example, Rachel Rosen simply answers "I'd kill it" to the first question), and show little or no involuntary response.