diff --git a/R/xpl-data-exam.R b/R/xpl-data-exam.R
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+++ b/R/xpl-data-exam.R
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+#' Dummy data set for Cochran's Q test
+#'
+#' A dataset containing information about results of three exams.
+#'
+#' @format A data frame with 15 rows and 3 variables:
+#' \describe{
+#'   \item{exam1}{result of exam1}
+#'   \item{exam2}{result of exam2}
+#'   \item{exam3}{result of exam3}
+#' }
+#'
+#' @source \url{http://www.spss-tutorials.com/spss-cochran-q-test/}
+"exam"
diff --git a/R/xpl-data-hsb.R b/R/xpl-data-hsb.R
new file mode 100644
index 0000000..3c6b30c
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+++ b/R/xpl-data-hsb.R
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+#' High School and Beyond Data Set
+#'
+#' A dataset containing demographic information and standardized test
+#' scores of high school students.
+#'
+#' @format A data frame with 200 rows and 10 variables:
+#' \describe{
+#'   \item{id}{id of the student}
+#'   \item{female}{gender of the student}
+#'   \item{race}{ethnic background of the student}
+#'   \item{ses}{socio-economic status of the student}
+#'   \item{schtyp}{school type}
+#'   \item{prog}{program type}
+#'   \item{read}{scores from test of reading}
+#'   \item{write}{scores from test of writing}
+#'   \item{math}{scores from test of math}
+#'   \item{science}{scores from test of science}
+#'   \item{socst}{scores from test of social studies}
+#' }
+#'
+#' @source \url{http://www.ats.ucla.edu/stat/spss/whatstat/whatstat.htm}
+"hsb"
diff --git a/R/xpl-data-treatment.R b/R/xpl-data-treatment.R
new file mode 100644
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+++ b/R/xpl-data-treatment.R
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+#' Dummy data set for 2 Sample Proportion test
+#'
+#' A dataset containing information about two treatments
+#'
+#' @format A data frame with 50 rows and 2 variables:
+#' \describe{
+#'   \item{treatment1}{result of treatment type 1}
+#'   \item{treatment2}{result of treatment type 2}
+#' }
+#'
+"treatment"
diff --git a/man/exam.Rd b/man/exam.Rd
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+++ b/man/exam.Rd
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+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/xpl-data-exam.R
+\docType{data}
+\name{exam}
+\alias{exam}
+\title{Dummy data set for Cochran's Q test}
+\format{
+A data frame with 15 rows and 3 variables:
+\describe{
+  \item{exam1}{result of exam1}
+  \item{exam2}{result of exam2}
+  \item{exam3}{result of exam3}
+}
+}
+\source{
+\url{http://www.spss-tutorials.com/spss-cochran-q-test/}
+}
+\usage{
+exam
+}
+\description{
+A dataset containing information about results of three exams.
+}
+\keyword{datasets}
diff --git a/man/hsb.Rd b/man/hsb.Rd
new file mode 100644
index 0000000..b6ad1e7
--- /dev/null
+++ b/man/hsb.Rd
@@ -0,0 +1,33 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/xpl-data-hsb.R
+\docType{data}
+\name{hsb}
+\alias{hsb}
+\title{High School and Beyond Data Set}
+\format{
+A data frame with 200 rows and 10 variables:
+\describe{
+  \item{id}{id of the student}
+  \item{female}{gender of the student}
+  \item{race}{ethnic background of the student}
+  \item{ses}{socio-economic status of the student}
+  \item{schtyp}{school type}
+  \item{prog}{program type}
+  \item{read}{scores from test of reading}
+  \item{write}{scores from test of writing}
+  \item{math}{scores from test of math}
+  \item{science}{scores from test of science}
+  \item{socst}{scores from test of social studies}
+}
+}
+\source{
+\url{http://www.ats.ucla.edu/stat/spss/whatstat/whatstat.htm}
+}
+\usage{
+hsb
+}
+\description{
+A dataset containing demographic information and standardized test
+scores of high school students.
+}
+\keyword{datasets}
diff --git a/man/treatment.Rd b/man/treatment.Rd
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+++ b/man/treatment.Rd
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+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/xpl-data-treatment.R
+\docType{data}
+\name{treatment}
+\alias{treatment}
+\title{Dummy data set for 2 Sample Proportion test}
+\format{
+A data frame with 50 rows and 2 variables:
+\describe{
+  \item{treatment1}{result of treatment type 1}
+  \item{treatment2}{result of treatment type 2}
+}
+}
+\usage{
+treatment
+}
+\description{
+A dataset containing information about two treatments
+}
+\keyword{datasets}