Index: Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Forms/Views/ClosingStructuresScenariosView.cs
===================================================================
diff -u -rb23612b7fdc45eb275697f50a94756386d3c2c39 -r74f04a12c7ff3bbba6746e2abfb7d7ee83cc29f3
--- Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Forms/Views/ClosingStructuresScenariosView.cs	(.../ClosingStructuresScenariosView.cs)	(revision b23612b7fdc45eb275697f50a94756386d3c2c39)
+++ Ringtoets/ClosingStructures/src/Ringtoets.ClosingStructures.Forms/Views/ClosingStructuresScenariosView.cs	(.../ClosingStructuresScenariosView.cs)	(revision 74f04a12c7ff3bbba6746e2abfb7d7ee83cc29f3)
@@ -56,7 +56,9 @@
 
             // The concat is needed to observe the input of calculations in child groups.
             calculationInputObserver = new RecursiveObserver<CalculationGroup, ICalculationInput>(
-                UpdateDataGridViewDataSource, cg => cg.Children.Concat<object>(cg.Children.OfType<ICalculation>().Select(c => c.GetObservableInput())));
+                UpdateDataGridViewDataSource, cg => cg.Children.Concat<object>(cg.Children
+                                                                                 .OfType<StructuresCalculation<ClosingStructuresInput>>()
+                                                                                 .Select(c => c.InputParameters)));
             calculationGroupObserver = new RecursiveObserver<CalculationGroup, ICalculationBase>(UpdateDataGridViewDataSource, c => c.Children);
         }
 
Index: Ringtoets/Common/src/Ringtoets.Common.Data/Calculation/ICalculation.cs
===================================================================
diff -u -r1051f838aebbd5977351542027ce6330583b0d43 -r74f04a12c7ff3bbba6746e2abfb7d7ee83cc29f3
--- Ringtoets/Common/src/Ringtoets.Common.Data/Calculation/ICalculation.cs	(.../ICalculation.cs)	(revision 1051f838aebbd5977351542027ce6330583b0d43)
+++ Ringtoets/Common/src/Ringtoets.Common.Data/Calculation/ICalculation.cs	(.../ICalculation.cs)	(revision 74f04a12c7ff3bbba6746e2abfb7d7ee83cc29f3)
@@ -35,15 +35,5 @@
         /// Clears the calculated output.
         /// </summary>
         void ClearOutput();
-
-        /// <summary>
-        /// Gets the input of the calculation to observe.
-        /// </summary>
-        ICalculationInput GetObservableInput();
-
-        /// <summary>
-        /// Gets the output of the calculation to observe.
-        /// </summary>
-        ICalculationOutput GetObservableOutput();
     }
 }
\ No newline at end of file
Index: Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.Forms/Views/GrassCoverErosionInwardsScenariosView.cs
===================================================================
diff -u -rb23612b7fdc45eb275697f50a94756386d3c2c39 -r74f04a12c7ff3bbba6746e2abfb7d7ee83cc29f3
--- Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.Forms/Views/GrassCoverErosionInwardsScenariosView.cs	(.../GrassCoverErosionInwardsScenariosView.cs)	(revision b23612b7fdc45eb275697f50a94756386d3c2c39)
+++ Ringtoets/GrassCoverErosionInwards/src/Ringtoets.GrassCoverErosionInwards.Forms/Views/GrassCoverErosionInwardsScenariosView.cs	(.../GrassCoverErosionInwardsScenariosView.cs)	(revision 74f04a12c7ff3bbba6746e2abfb7d7ee83cc29f3)
@@ -55,7 +55,9 @@
 
             // The concat is needed to observe the input of calculations in child groups.
             calculationInputObserver = new RecursiveObserver<CalculationGroup, ICalculationInput>(
-                UpdateDataGridViewDataSource, cg => cg.Children.Concat<object>(cg.Children.OfType<ICalculation>().Select(c => c.GetObservableInput())));
+                UpdateDataGridViewDataSource, cg => cg.Children.Concat<object>(cg.Children
+                                                                                 .OfType<GrassCoverErosionInwardsCalculation>()
+                                                                                 .Select(c => c.InputParameters)));
             calculationGroupObserver = new RecursiveObserver<CalculationGroup, ICalculationBase>(UpdateDataGridViewDataSource, c => c.Children);
         }
 
Index: Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Forms/Views/HeightStructuresScenariosView.cs
===================================================================
diff -u -r183d1e7ed095ea4e8024068bc4ddfcf3ac6997d3 -r74f04a12c7ff3bbba6746e2abfb7d7ee83cc29f3
--- Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Forms/Views/HeightStructuresScenariosView.cs	(.../HeightStructuresScenariosView.cs)	(revision 183d1e7ed095ea4e8024068bc4ddfcf3ac6997d3)
+++ Ringtoets/HeightStructures/src/Ringtoets.HeightStructures.Forms/Views/HeightStructuresScenariosView.cs	(.../HeightStructuresScenariosView.cs)	(revision 74f04a12c7ff3bbba6746e2abfb7d7ee83cc29f3)
@@ -56,7 +56,9 @@
 
             // The concat is needed to observe the input of calculations in child groups.
             calculationInputObserver = new RecursiveObserver<CalculationGroup, ICalculationInput>(
-                UpdateDataGridViewDataSource, cg => cg.Children.Concat<object>(cg.Children.OfType<ICalculation>().Select(c => c.GetObservableInput())));
+                UpdateDataGridViewDataSource, cg => cg.Children.Concat<object>(cg.Children
+                                                                                 .OfType<StructuresCalculation<HeightStructuresInput>>()
+                                                                                 .Select(c => c.InputParameters)));
             calculationGroupObserver = new RecursiveObserver<CalculationGroup, ICalculationBase>(UpdateDataGridViewDataSource, c => c.Children);
         }
 
Index: Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.Forms/Views/StabilityPointStructuresScenariosView.cs
===================================================================
diff -u -r6af0f01bd9b9b6da145bea0b4f8b8b1b4b09e02b -r74f04a12c7ff3bbba6746e2abfb7d7ee83cc29f3
--- Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.Forms/Views/StabilityPointStructuresScenariosView.cs	(.../StabilityPointStructuresScenariosView.cs)	(revision 6af0f01bd9b9b6da145bea0b4f8b8b1b4b09e02b)
+++ Ringtoets/StabilityPointStructures/src/Ringtoets.StabilityPointStructures.Forms/Views/StabilityPointStructuresScenariosView.cs	(.../StabilityPointStructuresScenariosView.cs)	(revision 74f04a12c7ff3bbba6746e2abfb7d7ee83cc29f3)
@@ -56,7 +56,9 @@
 
             // The concat is needed to observe the input of calculations in child groups.
             calculationInputObserver = new RecursiveObserver<CalculationGroup, ICalculationInput>(
-                UpdateDataGridViewDataSource, cg => cg.Children.Concat<object>(cg.Children.OfType<ICalculation>().Select(c => c.GetObservableInput())));
+                UpdateDataGridViewDataSource, cg => cg.Children.Concat<object>(cg.Children
+                                                                                 .OfType<StructuresCalculation<StabilityPointStructuresInput>>()
+                                                                                 .Select(c => c.InputParameters)));
             calculationGroupObserver = new RecursiveObserver<CalculationGroup, ICalculationBase>(UpdateDataGridViewDataSource, c => c.Children);
         }