Not really. This step basically says either "Look at the data and use that to guide how you write your algorithms" or "manually curate a statistically significa

Not really. This step basically says either "Look at the data and use that to guide how you write your algorithms" or "manually curate a statistically significant set of training data." You're not having the humans look at the data and include/exclude links or sites, you're having them look at the data to figure out heuristics for applying to the eight hundred billion pages they didn't look at. This step doesn't need to scale, so manual labor is not an incorrect solution. Given the context, and the ever-evolving nature of SEO, having human review is necessary part of the process, and this is the best way to add that human element in a scalable fashion.