"We chose to use these keywords (abortion, gun control and obama) because they are both a) searches where many people want unbiased results..."
I suspect that someone searching for these keywords are looking for reinforcement of their predetermined beliefs. Which is exactly what personalized search would do.
[edit] I've been downvoted so I feel I should clarify. I'm saying that these keywords are "magic" for a reason. This test should be performed using keywords people actually want unbiased results for. A good example would be a good javascript library for making graphs. (something I searched for yesterday and wanted to see an unbiased comparison). These keywords return biased results because they are highly polarized topics and you probably situate yourself on one of those poles - not in the middle. If google knows this about you, good for them and you because you found what you were looking for.
I suspect that someone searching for these keywords are looking for reinforcement of their predetermined beliefs. Which is exactly what personalized search would do.
[edit] I've been downvoted so I feel I should clarify. I'm saying that these keywords are "magic" for a reason. This test should be performed using keywords people actually want unbiased results for. A good example would be a good javascript library for making graphs. (something I searched for yesterday and wanted to see an unbiased comparison). These keywords return biased results because they are highly polarized topics and you probably situate yourself on one of those poles - not in the middle. If google knows this about you, good for them and you because you found what you were looking for.