Descriptive statistics of standardized scale and theta scores, by year (not weighted)

1998 2010
N (Mean, sd) Min Max N (Mean, sd) Min Max
Scale score–reading 17,620 (0,1) -1.39 10.13 15,670 (0,1) -2.4 4.06
Theta score–reading 17,620 (0,1) -2.72 4.30 15,670 (0,1) -3.47 5.01
Scale score–math 18,640 (0,1) -1.69 9.86 15,600 (0,1) -2.22 4.23
Theta score–math 18,640 (0,1) -3.13 4.48 15,600 (0,1) -5.78 6.28

Note: N is rounded to the nearest multiple of 10.

Source: ECLS-K, kindergarten classes of 1998–1999 and 2010–2011 (National Center for Education Statistics)

View the underlying data on epi.org.