Inside Google Translate

Have you ever wondered how Google Translate creates your translations?

Google Translate is a free tool that enables you to translate sentences, documents and

even whole websites instantly.

But how exactly does it work? While it may seem like we have a room full of bilingual

elves working for us, in fact all of our translations come from computers. These computers use a

process called “statistical machine translation” -- which is just a fancy way to say that our computers

generate translations based on patterns found in large amounts of text.

But let’s take a step back. If you want to teach someone a new language you might

start by teaching them vocabulary words and grammatical rules that explain how to construct

sentences. A computer can learn a foreign language the same way - by referring to vocabulary

and a set of rules.

But languages are complicated and, as any language learner can tell you, there are exceptions

to almost any rule. When you try to capture all of these exceptions, and exceptions to

the exceptions, in a computer program, the translation quality begins to break down.

Google Translate takes a different approach. Instead of trying to teach our computers all

the rules of a language, we let our computers discover the rules for themselves. They do

this by analyzing millions and millions of documents that have already been translated

by human translators. These translated texts come from books, organizations like the UN

and websites from all around the world.

Our computers scan these texts looking for statistically significant patterns--that is

to say, patterns between the translation and the original text that are unlikely to occur

by chance. Once the computer finds a pattern, it can use this pattern to translate similar

texts in the future. When you repeat this process billions of times you end up with

billions of patterns and one very smart computer program.

For some languages however we have fewer translated documents available and therefore fewer patterns

that our software has detected. This is why our translation quality will vary by language

and language pair. We know our translations aren’t always perfect but by constantly

providing new translated texts we can make our computers smarter and our translations

better.

So next time you translate a sentence or webpage with Google Translate, think about those millions

of documents and billions of patterns that ultimately led to your translation - and all

of it happening in the blink of an eye.

Pretty cool, isn’t it?

Give it a try at translate.google.com.