Avg. effectiveness - prioritizes treatments that have provided the greatest overall benefit, with the fewest negative effects.
Popularity - shows which treatments have been tried by the largest number of people.
% reporting major improvement - looks for treatments most likely to provide major improvement, regardless of the risk of negative effects. Some treatments may have an OK average score but may provide great benefit to a significant number of people who don't react negatively.
Note: Effectiveness rankings are adjusted by the relative number of votes.