How Google Gets You to Tag Their Images

Searching for images online is much different than searching for text. A computer program can search text throughout the Internet and tell you what's on it. However, it can not scan an image and describe it. This requires an actual person to look at the picture and type "keywords" describing what's in it. With so many pictures available online, how can this possibly be done? One person may describe a picture in completely different words than another person would. It would literally require several people to sit at a computer for hours and tag each image. This would be very costly and very time consuming.

Luis von Ahn of Carnegie Mellon University came up with a brilliant idea in 2006. His idea was to incorporate this task into an addicting game where people would actually want to do this, hence The ESP Game. When you log on to www.gwap.com to play the game, you are actually labeling images for Google. I was so impressed with this, I just had to write an article about it.

The idea of the game is to look at an image and try to come up with a matching word with your partner. You don't know who your partner is as you are randomly assigned one. The two of you will type in words describing the picture until you both have entered a matching word. You try to match as many as you can within the given time frame. Points are awarded. If a long time has passed with entering in words and you and your partner haven't agreed, you can click on "pass". However, Google still stores the words that you had typed in as a guess. When playing again, you get matched up with a different partner and do it again. It's not the same partner every time.

The left hand side of the screen displays the top scores which motivates the players to keep playing. They want to see their handle name displayed up on that list.

Then, what the game does is match all the words that people input and turn them into "tags" or "keywords" to describe the picture. Once they have gathered enough information on one photo, they bring in another one. So, when playing you always get different photos to describe.

What makes this game challenging is sometimes there are "taboo" words. These are words displayed that you cannot use to make a match, so you have to come up with something else. These are words that Google already has enough data on! They need some more words to describe the picture with.

Luis von Ahn has even worked out a way to prevent cheaters from entering in phony labels! He tossed in what he calls "test" images. These are pictures that the game has already figured out the best tags for. If you and your partner aren't entering these in, you can still play, but your answers won't be used for actually tagging the image.

When I heard about this, I logged in to play and see what it was all about. The idea was for me to play once. I ended up playing quite a few times. It really is a very addicting game. It's so addicting that there are people that have played this game over 20 hours in a given week!

I highly suggest you take a look at this video taken of Luis von Ahn talking about the game. I found myself chuckling a few times throughout the course of watching it. He takes you through the process involved and the idea behind creating the game, goes into why and how it works and talks about why people love the game so much.