Using the user agent string the page returned provided appropriate instructions for Chrome/Firefox/Safari/IE browsers and MacOS/Windows operating systems.
Eli Pariser's TED talk on Filter Bubble, got the interwebs talking on possible cons of personalization in search engine results.
Despite the popularity of the talk, there was no metric to understand whether users are aware of it or how to measure this inherent bias in the results.
Asked the turkers to run given set search queries on Google, Yahoo, Bing, and DuckDuckGo search engines and return the results page's source.
The form progress and steps are shown on top with a progress bar which is color coded with the primary color of the search engine.
As most of the steps remained same for subsequent steps except for the link for the query it was easy to miss this subtle change. To bring turker's attention to it, the url animated to get user's attention, telling them it had changed from the previous step.