diff --git a/integration-tests/run.sh b/integration-tests/run.sh
index d51dedf1ae15ace6fad09737c9fe171e49619806..98df72c37215c38ea8c4bd419aa8ec4e7ccbffb9 100755
--- a/integration-tests/run.sh
+++ b/integration-tests/run.sh
@@ -442,15 +442,28 @@ function assert_pattern_present {
 function generate_test_data {
     echo Generate incoming data
     local DIR=$DATA/in-raw
+    
+    # drop an identifyable valid data set
+    copy_test_data 3VCP1 $DIR
+    sleep 30
+    
+    # drop 3VCP1 twice which should yield an error (same external data set code)
     copy_test_data 3VCP1 $DIR
     sleep 30
+    
+    # drop an identifyable invalid data set (wrong image name, missing plate)
     copy_test_data 3VCP3 $DIR
     sleep 30
+    
+    # drop an identifyable invalid data set (missing TIFF folder)
     copy_test_data 3VCP4 $DIR
     sleep 30
+    
+    # drop an unidentifyable data set
     copy_test_data UnknownPlate $DIR
     sleep 30
     
+    # drop 3VCP1 again but this time it is a valid data set
     copy_test_data 3VCP3 $DATA
     mv $DATA/3VCP3/TIFF/blabla_3VCP1_K13_8_w460.tif  $DATA/3VCP3/TIFF/blabla_3VCP3_K13_8_w460.tif
     echo image for well M03 > $DATA/3VCP3/TIFF/blabla_3VCP3_M03_2_w350.tif