About the list:

Our Best Contractors come from popular home improvement categories and must qualify for the prestigious 2011 Angie's List Super Service Award, which requires they have a current and overall grade of A and be in good standing with Angie's List. The Best also must have had a flawless - or nearly flawless - overall record, a minimum of six reports and multiple Page of Happiness nominations in the reporting period. These requirements put them in the top 1 percent of contractors eligible for the SSA.

To determine the Worst Contractors, we scrutinized member reports, Penalty Box cases and court records. We also interviewed scores of sources, basing our selections on the gravity or volume of allegations and the amount of damage customers say those contractors inflicted. In the More Worst Contractors section, we listed companies that remain in the Angie's List Penalty Box.

Finally, in keeping with our tougher stance on trade licensing, the Angie's List Trade Licensing Department audited every Best Contractor finalist for compliance with state and local laws. We booted those unable to produce a valid trade license or prove they didn't need one. If a Worst Contractor lacked a required trade license, we included information on their noncompliant status.