star: Student Teacher Achievement Ratio (STAR) project data
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Data from Tennessee's Student Teacher Achievement Ratio (STAR) project which was a large-scale, four-year study of the effect of reduced class size.

1	data(star)

A data frame with 26796 observations on the following 18 variables.

id: a factor - student id number
sch: a factor - school id number
gr: grade - an ordered factor with levels K < 1 < 2 < 3
cltype: class type - a factor with levels small, reg and reg+A. The last level indicates a regular class size with a teachers aide.
hdeg: highest degree obtained by the teacher - an ordered factor with levels ASSOC < BS/BA < MS/MA/MEd < MA+ < Ed.S < Ed.D/Ph.D
clad: career ladder position of the teacher - a factor with levels NOT APPR PROB PEND 1 2 3
exp: a numeric vector - the total number of years of experience of the teacher
trace: teacher's race - a factor with levels W, B, A, H, I and O representing white, black, Asian, Hispanic, Indian (Native American) and other
read: the student's total reading scaled score
math: the student's total math scaled score
ses: socioeconomic status - a factor with levels F and N representing eligible for free lunches or not eligible
schtype: school type - a factor with levels inner, suburb, rural and urban
sx: student's sex - a factor with levels M F
eth: student's ethnicity - a factor with the same levels as trace
birthq: student's birth quarter - an ordered factor with levels 1977:1 < ... < 1982:2
birthy: student's birth year - an ordered factor with levels 1977:1982
yrs: number of years of schooling for the student - a numeric version of the grade gr with Kindergarten represented as 0. This variable was generated from gr and does not allow for a student being retained.
tch: a factor - teacher id number

Details of the original data source and the process of conversion to this representation are given in the vignette.

http://www.heros-inc.org/data.htm

str(star)

Loading required package: lme4
Loading required package: Matrix
'data.frame':	26796 obs. of  18 variables:
 $ id     : Factor w/ 11598 levels "100017","100028",..: 1 2 3 3 3 4 5 5 6 6 ...
 $ sch    : Factor w/ 80 levels "1","2","3","4",..: 28 52 41 41 41 64 40 40 22 22 ...
 $ gr     : Ord.factor w/ 4 levels "K"<"1"<"2"<"3": 1 1 2 3 4 1 1 2 1 2 ...
 $ cltype : Factor w/ 3 levels "small","reg",..: 1 2 1 1 1 1 2 3 1 1 ...
 $ hdeg   : Ord.factor w/ 6 levels "ASSOC"<"BS/BA"<..: 2 3 2 3 2 2 2 2 2 3 ...
 $ clad   : Factor w/ 7 levels "NOT","APPR","PROB",..: 5 5 5 2 5 5 2 5 3 5 ...
 $ exp    : int  3 12 20 15 5 19 2 5 9 9 ...
 $ trace  : Factor w/ 6 levels "W","B","A","H",..: 2 1 1 2 1 1 1 1 2 2 ...
 $ read   : int  476 410 507 575 610 430 495 629 418 524 ...
 $ math   : int  602 444 572 620 655 484 576 592 489 567 ...
 $ ses    : Factor w/ 2 levels "F","N": 1 2 2 2 2 2 1 1 1 1 ...
 $ schtype: Factor w/ 4 levels "inner","suburb",..: 1 2 2 2 2 3 3 3 1 1 ...
 $ sx     : Factor w/ 2 levels "M","F": 2 2 1 1 1 2 2 2 2 2 ...
 $ eth    : Factor w/ 6 levels "W","B","A","H",..: 2 1 1 1 1 1 1 1 2 2 ...
 $ birthq : Ord.factor w/ 25 levels "1977:1"<"1977:2"<..: 14 15 15 15 15 14 12 12 14 14 ...
 $ birthy : Ord.factor w/ 6 levels "1977"<"1978"<..: 4 4 4 4 4 4 3 3 4 4 ...
 $ yrs    : num  0 0 1 2 3 0 0 1 0 1 ...
 $ tch    : Factor w/ 1387 levels "1","2","3","4",..: 478 893 698 701 706 1102 679 684 351 359 ...