It doesn’t need to be accurate; not in the slightest. It just needs to be directionally correct. Small data points produce quite decent results and the marginal value of new data points very quickly approaches zero.
💯 Previously, I set the WoT of the coracle boat to 1, but there was no spam and it worked fine. However, most Japanese currently have zero WoT, and if I set my coacle's WoT setting to 1, almost nothing will be displayed. I don't know if it's a problem with the coracle or my own.