The Turing Test

I’ve talked a lot about artificial intelligence on this blog. But what does “artificial intelligence” really mean?

How do we know if a machine is thinking?

One answer comes from Alan Turing (1912-1954):

One at a time, ladies.

Turing, like others I could name, was a professional badass. Among his more notable accomplishments:

  • Widely considered the father of computer science
  • Instrumental in breaking Enigma, the Nazi secret code
  • Creator of the Turing Machine, a simple mathematical model for a computer, which Google recently featured on their homepage

Unfortunately for Turing, he was gay – more specifically, gay in 1950s England – which, at the time, was a criminal offense. He was “treated” with female hormones to avoid going to prison. Two years later, when he died from cyanide poisoning, it was ruled a suicide.

But back to our question. Can machines think?

Turing argued that the question, while interesting, tends to get mired in murky philosophical discussion about the meaning of the word “think.” He suggested we consider an alternative question, one that’s easier to define and has measurable results.

Suppose you’re chatting with someone online, using an instant messenger like AIM or MS Communicator. How do you know if the other person is a human or a computer? Today, it’s easy. Although there are so-called “chatbots” that simulate a human chat partner, none of them is likely to fool you for long. But Turing suggested that if a computer program was so sophisticated that you couldn’t tell whether you were talking to a human or not, then that’s a pretty good sign you’re looking at intelligence. This chat experiment is called the Turing Test.

Of course you’d have to define some parameters for the experiment. Who’s doing the testing – an average Joe or a savvy AI expert? How long does the test last? Etc. But these are fairly minor details, in my opinion.

It’s important to note, as Turing himself did, that the Turing Test should be considered sufficient but not necessary to establish intelligence. That is, a machine that passes the Turing Test might be judged intelligent, but a machine that fails the test is not necessarily unintelligent. It might simply be intelligent in other ways that don’t involve acting like a human.

The Turing Test has come under a lot of criticism from a lot of different angles. One argument says that the Test is a distraction from “serious” AI research, which today is highly specialized into specific intelligence problems, and rarely involves chatting. I’d counter that on two levels. First, as I just mentioned, Turing never claimed the test was the only definition of intelligence, so it isn’t supposed to be all-encompassing. But second, I have the feeling that by hyperspecializing, the AI community has lost its way. Researchers, it seems, have largely given up (at least for now) on creating a general-purpose, human-level intelligence capable of passing the Turing Test. I think that’s a mistake.

Another, more philosophical criticism says that a machine might pass the Turing Test by acting like it’s thinking, but not really be thinking. Tomorrow I’ll talk about that argument in more depth.

In the meantime – what do you think about the Turing Test? If a computer could pass this test, would you consider it intelligent?


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s