diff --git a/NAMESPACE b/NAMESPACE
index 7cb0032e6e2431ce5dc0d7c3ad3658ff9f687399..bdaccf3f5299a10dc9229dce0dbf03da4c944cc3 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -1,6 +1,7 @@
 # Generated by roxygen2: do not edit by hand
 
 export("%>%")
+export(apollo_ztest)
 export(createSets)
 export(poetest)
 export(quicktexregapollo)
diff --git a/R/apollo_ztest.R b/R/apollo_ztest.R
index bbe6511ac4311a2f6f19d145c11a7e3e0d513435..3fbd3b698dace0b403b568233904d5223c2b3cea 100644
--- a/R/apollo_ztest.R
+++ b/R/apollo_ztest.R
@@ -1,6 +1,17 @@
 
-#z-test with apollo data
 
+
+#' Perform a z test to compare parameters from two models which were estimated with apollo
+#'
+#'Use this test if you estimate the exact same model with different data sets. For example, if you have a split sample and want to compare the two samples for differences in preferences. The test is especially useful for models in WTP Space where the Poe Test ist not adequate.
+#' @param model1 Model from which to take the first parameter
+#' @param model2 Model from which to take the second parameter
+#' @param hyp Your hypotheses to test. Default is 0 which means you test for equality of parameters. Currently there are no other options. If you change the value, it will still test for equality (0)
+#'
+#' @return a dataframe with the test statistics
+#' @export
+#'
+#' @examples \dontrun apollo_ztest(model1,model2)
 apollo_ztest <- function(model1, model2, hyp=0){
 
   comp = data.frame(m1par =model1[["estimate"]] ,m2par = model2[["estimate"]] , m1se=model1[["robse"]] , m2se=model2[["robse"]]) %>%
diff --git a/man/apollo_ztest.Rd b/man/apollo_ztest.Rd
new file mode 100644
index 0000000000000000000000000000000000000000..d82bd9ee2a5344828d6f482fceb3f9b6044f5fd8
--- /dev/null
+++ b/man/apollo_ztest.Rd
@@ -0,0 +1,24 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/apollo_ztest.R
+\name{apollo_ztest}
+\alias{apollo_ztest}
+\title{Perform a z test to compare parameters from two models which were estimated with apollo}
+\usage{
+apollo_ztest(model1, model2, hyp = 0)
+}
+\arguments{
+\item{model1}{Model from which to take the first parameter}
+
+\item{model2}{Model from which to take the second parameter}
+
+\item{hyp}{Your hypotheses to test. Default is 0 which means you test for equality of parameters. Currently there are no other options. If you change the value, it will still test for equality (0)}
+}
+\value{
+a dataframe with the test statistics
+}
+\description{
+Use this test if you estimate the exact same model with different data sets. For example, if you have a split sample and want to compare the two samples for differences in preferences. The test is especially useful for models in WTP Space where the Poe Test ist not adequate.
+}
+\examples{
+\dontrun apollo_ztest(model1,model2)
+}