diff --git a/scripts/Inelastic/Direct/ReductionWrapper.py b/scripts/Inelastic/Direct/ReductionWrapper.py
index 804511d4bf6bc2d0a6c6e751a48ed6f2e1e32778..2a8ea37df779c22f709387636914ffa305299379 100644
--- a/scripts/Inelastic/Direct/ReductionWrapper.py
+++ b/scripts/Inelastic/Direct/ReductionWrapper.py
@@ -251,7 +251,22 @@ class ReductionWrapper(object):
         return None
 
     def evaluate_abs_corrections(self,test_ws,spectra_to_correct):
-        """ Evaluate absorption corrections from the """
+        """ Evaluate absorption corrections from the input workspace
+            Input:
+            test_ws -- the workspace to calculate corrections for.
+                       The corrections themselves should be defined by
+                       the following data reduction properties:
+                       propmen.correct_absorption_on = TheShapeOfTheSample -- define sample parameters
+                       propmen.abs_corr_info   = {} Dictionary with additional correction parameters
+                       (can be empty)
+             spectra_to_correct -- list of the spectra to correct absorption for.
+             If this list is empty, the corrections are calculated for the whole workspace,
+             which can cause problems for plotting.
+
+             Returns:
+             corrections -- the workspace containing the absorption corrections
+             for the spectra, specified in spectra_to_correct variable.
+        """
 
         n_spectra = test_ws.getNumberHistograms()
         decrement = len(spectra_to_correct)
diff --git a/scripts/test/MariReduction.py b/scripts/test/MariReduction.py
index 0c9c71c8b2c9d51fe7ea43d84e5ec8f940d02c66..72a8082ca46f60856266de9acd40f8ad3ea11d9e 100644
--- a/scripts/test/MariReduction.py
+++ b/scripts/test/MariReduction.py
@@ -75,11 +75,12 @@ class ReduceMARI(ReductionWrapper):
       #
       #Two generic algorithms are currently available to
       #    correct for absorption:
-      # a) AbsorptionCorrections (invoked by 'is_fast':True key of
-      #    abs_corr_info property and by default).
+      # a) MonteCarloAbsorption (invoked by 'is_mc':True key of abs_corr_info
+      #    property and by default)
       # and
-      # b) MonteCarloAbsorption (invoked by 'is_mc':True key of abs_corr_info
-      #    property)
+      # b) AbsorptionCorrections (invoked by 'is_fast':True key of
+      #    abs_corr_info property). This algorithm has number of optimizations
+      #    for the special shapes cases and need further scientific validations
 
       # All other properties, to be provided in the input dictionary of this
       # property are the non-sample related properties of the
@@ -249,15 +250,19 @@ class ReduceMARI(ReductionWrapper):
         # (or be reduced)
         if test_ws is None:
             test_ws = PropertyManager.sample_run.get_workspace()
-        # Define spectra list to test absorption on
+        # Define spectra list to test absorption on. Empty list will
+        # define absorption on the whole workspace.
         check_spectra = [1,200]
         # Evaluate corrections on the selected spectra of the workspace and the time to obtain
         # the corrections on the whole workspace.
         corrections,time_to_correct_abs = self.evaluate_abs_corrections(test_ws,check_spectra)
         # When accuracy and speed of the corrections is satisfactory, copy chosen abs_corr_info
         # properties from above to the advanced_porperties area to run in reduction.
-        if not mpl is None:
-            mpl.plotSpectrum(corrections,range(0,len(check_spectra)))
+        if mpl is not None:
+            n_spectra = len(check_spectra)
+            if n_spectra == 0:
+                n_specra = corrections.getNumberHistograms()
+            mpl.plotSpectrum(corrections,range(0,n_spectra))
         #
         return corrections
 
diff --git a/scripts/test/ReductionWrapperTest.py b/scripts/test/ReductionWrapperTest.py
index 800b73fa1cdc4003f3e333a0ddd3c3120c2dd686..377fd94a020879e97403b918bbc829416f1019fe 100644
--- a/scripts/test/ReductionWrapperTest.py
+++ b/scripts/test/ReductionWrapperTest.py
@@ -130,8 +130,8 @@ class ReductionWrapperTest(unittest.TestCase):
 
         import reduce_vars as rv
 
-        self.assertEqual(rv.standard_vars,main_prop)
-        self.assertEqual(rv.advanced_vars,adv_prop)
+        self.assertDictEqual(rv.standard_vars,main_prop)
+        self.assertDictEqual(rv.advanced_vars,adv_prop)
         self.assertTrue(hasattr(rv,'variable_help'))
 
         imp.reload(mr)