SII (Study of Intstructional Improvement) by researchers at the 
University of Michigan to study the math achievement scores of 
first- and third-grade students at randomly collected classrooms 
from a national U.S. sample of elementary schools. 

The classroom.csv dataset:
1,190 first grade students sampled from 312 classrooms in 107 schools. 

MATHGAIN: measures change in student math achievement scores from the
spring of kindergarten to the spring of first grade. 

Three-level dataset:
students (Level 1) are nested within classroms (Level 2), and 
classrooms are nested within schools (Level 3).

Goal: examine the contributions of selected student-level, classroom-level
and school-level covariates to the variation in math achievement gain.  

See p. 118 for description of variables in the analysis.

> class <- read.csv("http://www.rohan.sdsu.edu/~babailey/stat700/classroom.csv", header=T)

> class[1:5,]
  sex minority mathkind mathgain   ses yearstea mathknow housepov mathprep
1   1        1      448       32  0.46        1       NA    0.082     2.00
2   0        1      460      109 -0.27        1       NA    0.082     2.00
3   1        1      511       56 -0.03        1       NA    0.082     2.00
4   0        1      449       83 -0.38        2    -0.11    0.082     3.25
5   0        1      425       53 -0.03        2    -0.11    0.082     3.25
  classid schoolid childid
1     160        1       1
2     160        1       2
3     160        1       3
4     217        1       4
5     217        1       5