Google's reliance on multi-variate testing as part of their design decision-making process isn't news. However, let's say, you find that you might need to conduct a test to determine which shade of blue among 41 gradations should be used on a design. Enter Google Website Optimizer. Google's Look inside a 1,024 recipe multivariate experiment goes through how they used Google Website Optimizer to test the effectiveness and combinatorial impact of various elements on the YouTube (US) homepage. See if you can guess which combination was most effective.
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