Figures for the Pittsburgh Post-Gazette's Top 50 lists were derived from company reports, Bloomberg and Post-Gazette research.
Revenue, net income and return on equity data are based on the most recent fiscal year reports filed by each company as of the close of business on March 21. In most cases, that means the numbers are from the 2012 calendar year.
Stock price changes are for the 2012 calendar year. Market capitalization, which is based on shares outstanding and stock price, is based on the Dec. 31 closing price.
For overall rankings, an average score was determined for each of the seven performance categories: revenue, revenue change, net income, net income change, stock price change, market capitalization and return on equity.
Those averages were subtracted from individual company scores in each category, with the difference divided by the standard deviation for each of the categories to give each company a weighted score in each category.
The weighted scores for each company in each category were then added up to determine the overall scores.
An identical procedure was followed to arrive at the growth rankings, using the categories of revenue change, net income change, stock price change and return on equity.