Precision evaluations. Side-by-side experiments with human focus groups. Click evaluations. All of it led to more than 500 algorithm changes in 2010. Eric Schmidt is speaking today at a Senate subcommittee hearing in Washington, DC, about Google’s business practices, and answering claims that Google’s business practices are anti-competitive. As part of his appearance, Schmidt (as all witnesses do) prepared a set of written remarks that was submitted to the subcommittee prior to his appearance today. The subcommittee has released that document (PDF download), which contains an interesting section that reveals more details about how Google tests its algorithm changes.