This is 99% invisible. I'm Roman Mars.

When Joseph Weisenbaum was still alive, he liked to tell the story about a computer program he'd created back in the 1960s as a professor at MIT. It was a simple chatbot named

Eliza that could interact with users in a typed conversation. Wisenbaum

asked his secretary to try it out.

I asked her to my office and sat it down at the keyboard and then she began to type and of course I looked

over her shoulder to make sure that everything was operating properly.

Weisenbaum watched as the Secretary typed a message to Eliza and then as the program responded to her.

After two or three interchanges with the machine, she turned to me and she said,

would you mind leaving the room please?

The Secretary was so entranced by this chatbot

that she didn't want to stop exchanging messages.

Weisenbaum's secretary fell under the spell of the machine.

Weisenbaum saw this happening over and over again.

People would reveal very intimate details about their lives to the program.

It was like they just been waiting for someone,

for something to ask.

Eliza was a simple computer program.

That's producer Delaney Hall.

The way it worked was it would recognize a keyword in the user's statement

and then reflect it back in the form of a simple phrase or question.

When Eliza got confused or couldn't parse a statement,

it would fall back on set phrases like,

...