Google explains technology behind Instant search

Google has provided more details about the technology behind its recently launched Instant Search.

The system provides a live feed of search suggestions as the user types, and has already won widespread favour.

"Our key design challenge was to make sure people would notice relevant results without being distracted," said Ben Gomes, a distinguished engineer Google, in a blog post.

"We knew it would take extensive testing to find the right design, so we ran through a sequence of prototypes, usability studies (testing with people from the community), 'dogfooding' (testing with Google employees) and search experiments (testing with a small percentage of Google users)."

Initial trials revealed some problems, Gomes explained, such as the results appearing too slowly or in too complex a form, but these were overcome after continued user experiments.

The new feature raised some infrastructure challenges, however, and Google decided to create a technical solution rather than invest in more server capacity.

"When we came to the infrastructure team and said that we are going to be serving five to seven times as many results pages for each query performed in Google Instant, first they threw a fit, then they figured out how to get us there," said Gomes.

The solution involved a range of technical measures, including new caches that can cope with high refresh rates, and an optimised page-rendering JavaScript code designed to let the browser keep pace with the system.

Google expects to keep innovating with Instant search. "While it is a big change, I believe that we'll look back and wonder how search was ever any other way," said Gomes.