Accuracy and Reliability
Star ratings classify data reliability and absolute accuracy. This is important to understand because positional data is the basis for metrics and charts. Trails that I, personally, directly observe are always measured using a device accurate to within an acceptable range and data is always cleansed and corrected. This does not imply positional accuracy never deviates from true ground positions — it means much effort was made to close that gap.
Accuracy Ratings
Five Stars: The trail was measured using a device that is accurate to within an acceptable range and data was cleansed and corrected.
Four Stars: The trail was measured using a device that is accurate to within an acceptable range and data was not cleansed and corrected.
Three Stars: The trail was measured using a device that is not accurate to within an acceptable range and data was cleansed and corrected.
Two Stars: The trail was measured using a device that is not accurate to within an acceptable range and data was not cleansed and corrected.
One Star: The trail was not measured using a device.
No Stars: Not yet rated.
Reliability Ratings
Five Stars: The trail was directly observed by a trusted person who employed the skills of a GIS field analyst. (Data is correctly labeled and devoid of topological errors.)
Four Stars: The trail was directly observed by a trusted person who employed the skills of a GIS field analyst and/or the trail was remotely sensed by a trusted person who employed the skills of a GIS technician. (Data is correctly labeled and devoid of topological errors.)
Three Stars: The trail was directly observed by a trusted person who did not employ the skills of a GIS field analyst.
Two Stars: The trail was directly observed by an unknown person.
One Star: The trail was not directly observed.
No Stars: Not yet rated.
Crowdsourced Trails
Crowdsourced trails measured using smartphones by unknown people are rated with two stars because a smartphone is not accurate to within an acceptable range and the people in the crowd are not trusted because they are unknown. Crowdsourced trails are the most inaccurate and unreliable, save for trails not measured using a device and not directly observed.