Search for Google isn't so much as product as a search for perfection. Last year, the company made over 500 changes to the way its search system works, some algorithmic adjustments and some design revisions.

"Here at Google, we're constantly evolving," explained Google product manager Johanna Wright in a phone interview.

On Wednesday, Google's evolution continues with the launch of an enhanced search results page that makes it easier to find relevant search results.

"The new design refreshes and streamlines the look, feel and functionality of Google, making it easier to pinpoint what you're looking for," said Google VP of search products and user experience Marissa Mayer in a blog post.

Google has made its easier to restrict results to specific types of content using the left hand pane on its search results page. Options include: Everything, Images, Videos, Books, Maps, News, Shopping, Blogs, Updates, and Discussions.

The company has also made the design of the Web pages used to present search results of a specific type more consistent.

The query-related search tools, launched in May 2009 and located just below the content type selections in the left hand pane, now adjust to suit the chosen content type.

Selecting Images, for example, brings up the search-by-color query-related search tool.

Conducting a search for "rolling stones" returns a selection of similar bands in the "Something Different" selections in the left hand pane.

"If you switch to images, not only has main panel changed to show images but tools also changed to be more image focused," said Wright.

Google has even given its four-color logo a make over. It features a smoother gradient, brighter colors, and a reduced drop shadow.

Google isn’t making any metrics available to quantify how its changes affect user happiness, but rest assured that the revised Web pages have been thoroughly tested in the company's usability lab.