On Mon, Aug 25, 2014 at 12:21 PM, Ryan Kaldari <rkaldari@wikimedia.org> wrote:
You can get accurate information from bad or incomplete data.

The issue is not merely that data are incomplete like your tides example, it's that it's biased in many ways we can't quantify. 

If we care enough about this to monitor it on an ongoing basis, we should just do a better job of collecting accurate information. 

Steven Walling,
Product Manager