Thanks! Definitely a problem even for us. Right now, we're focusing on getting as many people to contribute as possible (over at http://levels.fyi/addcomp.html). We've tossed some ideas around about only showing / averaging the last 10 salaries submitted for a certain company and level and ensuring some minimum date of submission. Glassdoor also suffers from not having granularity of level for engineers and I think that may be why salary data is so broadly ranged.