survey (version 3.9-1)

api: Student performance in California schools

Description

The Academic Performance Index is computed for all California schools based on standardised testing of students. The data sets contain information for all schools with at least 100 students and for various probability samples of the data.

Usage

data(api)

source

Data were obtained from the survey sampling help pages of UCLA Academic Technology Services, at http://www.ats.ucla.edu/stat/stata/Library/svy_survey.htm.

Details

apipop is the entire population, apiclus1 is a cluster sample of school districts, apistrat is a sample stratified by stype, and apiclus2 is a two-stage cluster sample of schools within districts. The sampling weights in apiclus1 are incorrect (the weight should be 757/15) but are as obtained from UCLA.

References

The API program and original data files are at http://api.cde.ca.gov/

Examples

library(survey)
data(api)
mean(apipop$api00)
sum(apipop$enroll, na.rm=TRUE)

#stratified sample
dstrat<-svydesign(id=~1,strata=~stype, weights=~pw, data=apistrat, fpc=~fpc)
summary(dstrat)
svymean(~api00, dstrat)
svytotal(~enroll, dstrat, na.rm=TRUE)

# one-stage cluster sample
dclus1<-svydesign(id=~dnum, weights=~pw, data=apiclus1, fpc=~fpc)
summary(dclus1)
svymean(~api00, dclus1)
svytotal(~enroll, dclus1, na.rm=TRUE)

# two-stage cluster sample
dclus2<-svydesign(id=~dnum+snum, fpc=~fpc1+fpc2, data=apiclus2)
summary(dclus2)
svymean(~api00, dclus2)
svytotal(~enroll, dclus2, na.rm=TRUE)

# two-stage `with replacement'
dclus2wr<-svydesign(id=~dnum+snum, weights=~pw, data=apiclus2)
summary(dclus2wr)
svymean(~api00, dclus2wr)
svytotal(~enroll, dclus2wr, na.rm=TRUE)


# convert to replicate weights
rclus1<-as.svrepdesign(dclus1)
summary(rclus1)
svymean(~api00, rclus1)
svytotal(~enroll, rclus1, na.rm=TRUE)

# post-stratify on school type
pop.types<-xtabs(~stype, data=apipop)

rclus1p<-postStratify(rclus1, ~stype, pop.types)
dclus1p<-postStratify(dclus1, ~stype, pop.types)
summary(dclus1p)
summary(rclus1p)

svymean(~api00, dclus1p)
svytotal(~enroll, dclus1p, na.rm=TRUE)

svymean(~api00, rclus1p)
svytotal(~enroll, rclus1p, na.rm=TRUE)