Supporters and opponents of Edison Schools frequently butt heads over whether Edison-run schools are performing better than similar schools in the same districts. An article in The New York Times explores how the two sides can examine the same student achievement data and come to opposite conclusions, making several points along the way that are relevant to any effort to evaluate school effectiveness. "Complex calculations on academics," by Jacques Steinberg and Diana Henriques, The New York Times, July 16, 2002.