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)