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The real magic in Google Instant comes largely from advances in data-center hardware in the past 18 months, Hansson said. Faster servers and fatter connections between them are coupled with new tricks for caching the results for the majority of Google searches. Most searches typed by users aren’t very original. So when you type “bat” into Google, it’s statistically almost certain you’re going to keep going and type an additional “man” into the box. Rather than wait for you, Google sends over the results for “batman.”

“We make sure that searches on which we are confident get served fastest,” Hansson said. If your search query doesn’t seem obvious based on other people’s behavior, Google hangs back to see what else you type. In programmer-speak, Google has changed its back end from being “stateless,” which means that if you type five searches in a row, it treats each one as a whole new session, to maintaining a session state that tracks what search results have already been sent to you. That means a lot more computer memory work is going on inside Google’s data centers.

In the end, he said, Google Instant actually reduces the total cost of a search to the company by handing out the cached results for most searches. Separately, Google has updated its Internet crawlers to keep those cached results freshly stocked with the most recent news stories, blog posts, and other content that may be only a few minutes old.

The other big advancement happens inside your browser. Google research found that most people type at a rate which leaves a 300-millisecond gap between keystrokes. The goal for Google Instant, then, became to change the results in less than 300 milliseconds. To do that, engineers embarked on projects to optimize the JavaScript code that runs inside its pages so that search results and ads can be parsed and displayed onscreen in a couple of hundred milliseconds. JavaScript behavior varies a lot from one browser to the next. That meant that each of the four browsers supported by Google Instant–Internet Explorer, Apple’s Safari, Mozilla’s Firefox, and Google’s own Chrome– needed to be customized separately with different JavaScript code.

It’s no coincidence that these browsers’ JavaScript support has also been improved repeatedly in the past couple of years. As commercial websites add more and more interactivity, much of it powered by JavaScript, the performance of JavaScript has come to be the difference between fast and slow browsing most noticed by users oblivious to how the whole thing works. A year ago, a 300-millisecond response time would have probably been impossible. In the latest browsers, it’s become reliable.

Overall, Google claims that 15 separate technology innovations–most of them considered trade secrets–work together to make Google Instant possible.

Search Engine Land editor Danny Sullivan, a respected commentator, thinks that Google Instant could have another important business impact. He suggests it is less about running up more ad traffic and more about making competitors Bing and Yahoo seem slow. “I suspect that mainly, users will feel like Google is just faster,” he wrote in an e-mail. “If many of your queries are already the first thing that Google guesses at, the results are right there for you, immediately.” Asked if Google Instant will change the behavior of Internet users, he replied, “Your behavior is to be happier with Google.”

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Credit: Technology Review

Tagged: Web, Google, search, advertising, search engine, online advertising

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