The study showed participants Google search results on all queries, but switched around branding elements at the top and bottom of the page to label the results as from Yahoo, Microsoft Live Search, a startup called AI2RS, and Google.
From the paper:
Based on average relevance ratings, there was a 25% difference between the most highly rated search engine and the lowest, even though search engine results were identical in both content and presentation.The 25% difference was between the results branded with the AI2RS startup and the results branded as Yahoo.
Curiously, Yahoo was rated substantially higher than Google, despite the fact that these were Google's search results. Yahoo has failed to gain web search market share, but, if you believe this study, brand weakness is not the reason why.
It is true that this study is small, just 32 participants and across 4 different queries. It would be nice to see a broader study that confirms these results.
Even so, it probably is safe to say that the strength of the Google and Yahoo brands (and Microsoft's ownership of the defaults in Internet Explorer) make it very difficult for any web search startup. As Rich Skrenta once said, "A conventional attack against Google's search product will fail ... A copy of their product with your brand has no pull."
See also a lighter Penn State Live article on the study, "Branding matters -- even when searching".
[Found via Barry Schwartz]