Cumulative gains in Main NAEP, Long-Term Trend NAEP, and PISA reading scores, 1999/2000–2011 (standard deviations)
Note: The data point for PISA in 2006-07 is constructed by linear interpolation.
Source: Authors' analysis of National Center for Education Statistics’ NAEP Data Explorer and OECD Program for International Student Assessment (PISA) (2001, 2004, 2007, 2010a)
