Turner painting: A Quick Takes item in the Feb. 4 Calendar identified Christie's as the London auction house where the Getty Museum placed the high bid in 2010 for an 1839 painting by J.M.W. Turner. The sale was at Sotheby's.
Teacher effectiveness: An article in the Feb. 7 LATExtra section about a University of Colorado study of Los Angeles Unified School District teacher effectiveness said researchers found that up to 9% of math teachers and 12% of English teachers ended up in different categories than those in a separate analysis by The Times. These percentages referred only to teachers whom The Times rated as more effective than average but whom the Colorado researchers found to be indistinguishable from average. The story should have included an additional 7% of math teachers and 10% of English teachers whom The Times rated as less effective than average but, according to the Colorado study, were indistinguishable from average.