diff --git a/cace/common/common.py b/cace/common/common.py
index 32abbf1..94acab5 100644
--- a/cace/common/common.py
+++ b/cace/common/common.py
@@ -694,7 +694,8 @@ def run_subprocess(
         text=True,
     ) as process:
 
-        dbg(input)
+        if input != None:
+            dbg(f'input: {input}')
         stdout, stderr = process.communicate(input)
         returncode = process.returncode
 
diff --git a/cace/parameter/parameter.py b/cace/parameter/parameter.py
index b466e0c..1c57388 100755
--- a/cace/parameter/parameter.py
+++ b/cace/parameter/parameter.py
@@ -277,7 +277,7 @@ def get_result(self, name: str):
         return None
 
     def cancel(self, no_cb):
-        info(f'Parameter {self.pname}: Canceled')
+        info(f'Parameter {self.pname}: Canceled.')
         self.canceled = True
 
         if self.subproc_handle:
@@ -366,7 +366,8 @@ def run_subprocess(self, proc, args=[], env=None, input=None, cwd=None):
 
             self.subproc_handle = process
 
-            dbg(input)
+            if input != None:
+                dbg(f'input: {input}')
             stdout, stderr = process.communicate(input)
             returncode = process.returncode
 
@@ -497,14 +498,14 @@ def evaluate_result(self):
 
                         # Scale value with unit
                         if unit:
-                            dbg(f'{unit} {value}')
+                            dbg(f'scaling {value} with {unit}')
                             value = spice_unit_convert(
                                 (
                                     str(unit),
                                     str(value),
                                 )
                             )
-
+                            dbg(f'result: {value}')
                         if result != None:
                             dbg(
                                 f'Checking result {result} against value {value} with limit {limit}.'
@@ -893,7 +894,7 @@ def makeplot(
             not 'yaxis' in self.param['plot'][plot_name]
             and not 'xaxis' in self.param['plot'][plot_name]
         ):
-            err('Neither yaxis nor xaxis specified.')
+            err(f'Neither yaxis nor xaxis specified in plot {plot_name}.')
 
         xvariable = None
         if 'xaxis' in self.param['plot'][plot_name]:
@@ -1181,7 +1182,7 @@ def makeplot(
                 elif xvariable in conditions:
                     xvalues = conditions[xvariable].values
                 else:
-                    err(f'Unknown variable: {xvariable}')
+                    err(f'Unknown variable: {xvariable} in plot {plot_name}.')
                     return None
 
             xvalues_list.append(xvalues)
@@ -1196,7 +1197,9 @@ def makeplot(
                     elif yvariable in condition_set:
                         yvalues.append(condition_set[yvariable])
                     else:
-                        err(f'Unknown variable: {yvariable}')
+                        err(
+                            f'Unknown variable: {yvariable} in plot {plot_name}.'
+                        )
                         return None
 
             yvalues_list.append(yvalues)
diff --git a/cace/parameter/parameter_ngspice.py b/cace/parameter/parameter_ngspice.py
index 535a7db..b07b25f 100755
--- a/cace/parameter/parameter_ngspice.py
+++ b/cace/parameter/parameter_ngspice.py
@@ -62,7 +62,7 @@ def __init__(
             **kwargs,
         )
 
-        self.add_argument(Argument('template', None, True))
+        self.add_argument(Argument('template', None, True))   # TODO typing
         self.add_argument(Argument('collate', None, False))
         self.add_argument(Argument('format', None, False))
         self.add_argument(Argument('suffix', None, False))
@@ -153,7 +153,7 @@ def pre_start(self):
 
     def implementation(self):
 
-        info(f'Parameter {self.param["name"]}: Generating simulation files.')
+        info(f'Parameter {self.param["name"]}: Generating simulation files…')
 
         variables = self.get_argument('variables')
 
@@ -236,10 +236,11 @@ def implementation(self):
             dbg(f'Total number of simulations: {self.num_sims}')
 
             # If "collate" is set this means we need to merge
-            # the results of this variable
-            # This is done by removing it from the conditions
-            # and
+            # the results were all conditions but the collate conditions is the same
+            # This is useful for MC simulations, where the results of different iterations,
+            # but under the same conditions (e.g. temperature) should be collated.
 
+            # First remove the collate condition from the conditions
             if self.get_argument('collate'):
                 collate_variable = self.get_argument('collate')
                 info(f'Collating results using condition "{collate_variable}"')
@@ -249,7 +250,7 @@ def implementation(self):
                     dbg(collate_condition)
                 else:
                     err(
-                        f'Couldn\'t find collate variable "{collate_variable}" in conditions.'
+                        f'Couldn\'t find condition "{collate_variable}" used for collating the results.'
                     )
 
             # Generate the condition sets for each simulation
@@ -467,7 +468,7 @@ def implementation(self):
         # Run all simulations
         jobs = []
 
-        info(f'Parameter {self.param["name"]}: Running simulations.')
+        info(f'Parameter {self.param["name"]}: Running simulations…')
 
         self.cancel_point()
 
@@ -566,7 +567,7 @@ def implementation(self):
 
                 self.cancel_point()
 
-        info(f'Parameter {self.param["name"]}: Collecting results.')
+        info(f'Parameter {self.param["name"]}: Collecting results…')
 
         # Get the result
         max_digits = len(str(len(condition_sets)))
@@ -605,9 +606,6 @@ def implementation(self):
                     )
 
                 # Read the result file
-
-                collated_results = {}
-
                 if format == 'ascii':
 
                     result_file = os.path.join(
@@ -634,12 +632,18 @@ def implementation(self):
                                         collated_values[
                                             variables[_index]
                                         ].append(float(entry))
-
-                    dbg(f'collated_values: {collated_values}')
-
                 else:
                     err(f'Unsupported format for the simulation result.')
 
+            dbg(f'collated values: {collated_values}')
+
+            if self.get_argument('collate'):
+                condition_set[collate_variable] = collate_values
+
+                dbg(f'collated condition: {condition_set[collate_variable]}')
+
+            dbg(f'Extending final result…')
+
             for variable in variables:
                 if variable != None:
                     # Extend the final result
@@ -654,6 +658,10 @@ def implementation(self):
                     self.datasheet['paths']['scripts'], script
                 )
 
+                info(
+                    f"Running user-defined script '[repr.filename][link=file://{os.path.abspath(script_path)}]{os.path.relpath(script_path)}[/link][/repr.filename]'…"
+                )
+
                 if not os.path.isfile(script_path):
                     err(f'No such user script {script_path}.')
                     self.result_type = ResultType.ERROR
@@ -663,9 +671,33 @@ def implementation(self):
                     user_script = SourceFileLoader(
                         'user_script', script_path
                     ).load_module()
-                    collated_values = user_script.postprocess(
-                        collated_values, condition_set
-                    )
+
+                    class CustomPrint:
+                        def __enter__(self):
+                            self._stdout = sys.stdout
+                            sys.stdout = self
+                            return self
+
+                        def __exit__(self, *args):
+                            sys.stdout = self._stdout
+
+                        def write(self, text):
+                            text = text.rstrip()
+                            if len(text) == 0:
+                                return
+                            info(f'User script: {text}')
+
+                        def flush(self):
+                            self._stdout.flush()
+
+                        def __getattr__(self, attr):
+                            return getattr(self._stdout, attr)
+
+                    with CustomPrint() as output:
+                        collated_values = user_script.postprocess(
+                            collated_values, condition_set
+                        )
+
                 except Exception as e:
                     err(f'Error in user script: {e}')
                     self.result_type = ResultType.ERROR
diff --git a/default.nix b/default.nix
index 692748b..bb3fa24 100644
--- a/default.nix
+++ b/default.nix
@@ -31,6 +31,7 @@
   # Python
   matplotlib,
   numpy,
+  scipy,
   pillow,
   tkinter,
   rich,
@@ -77,6 +78,7 @@
         # Python
         matplotlib
         numpy
+        scipy
         pillow
         volare
         tkinter
diff --git a/docs/source/index.md b/docs/source/index.md
index 27c3cd7..2098ab8 100644
--- a/docs/source/index.md
+++ b/docs/source/index.md
@@ -24,7 +24,7 @@ Follow the navigation element below (or check the sidebar on the left) to get st
 getting_started/index
 usage/index
 reference_manual/index
-tutorial/index
+tutorials/index
 examples/index
 dev/index
 ```
diff --git a/docs/source/reference_manual/tools.md b/docs/source/reference_manual/tools.md
index 34e702e..3f1e3b2 100644
--- a/docs/source/reference_manual/tools.md
+++ b/docs/source/reference_manual/tools.md
@@ -13,8 +13,10 @@ Arguments:
 - `format`: `<'ascii'>` The file format of the ngspice result. Currently only `ascii` is supported.
 - `suffix`: `<string>` File extension of the result file. For example: `.data`.
 - `variables`: `<List[string|null]>` A list of results inside the result file. Use `null` to ignore a column.
+- `script` (optional): `<string>` Name of a Python script in the script folder. It will be executed on the results of each simulation.
+- `script_variables` (optional): `<List[string|null]>` A list of results generated by the specified Python script. These results are available in addition to the ones specified under `variables`. TODO
 
-Results: The results depend on the `variables` argument.
+Results: The results depend on the `variables` and optionally the `script_variables` arguments.
 
 ## `magic_drc`
 
diff --git a/docs/source/tutorials/custom_scripts.md b/docs/source/tutorials/custom_scripts.md
new file mode 100644
index 0000000..144320a
--- /dev/null
+++ b/docs/source/tutorials/custom_scripts.md
@@ -0,0 +1,2 @@
+# Tutorial - Using Custom Scripts to Preprocess Simulation Results
+
diff --git a/docs/source/tutorial/img/cli_1.png b/docs/source/tutorials/img/cli_1.png
similarity index 100%
rename from docs/source/tutorial/img/cli_1.png
rename to docs/source/tutorials/img/cli_1.png
diff --git a/docs/source/tutorial/img/cli_2.png b/docs/source/tutorials/img/cli_2.png
similarity index 100%
rename from docs/source/tutorial/img/cli_2.png
rename to docs/source/tutorials/img/cli_2.png
diff --git a/docs/source/tutorial/img/cli_3.png b/docs/source/tutorials/img/cli_3.png
similarity index 100%
rename from docs/source/tutorial/img/cli_3.png
rename to docs/source/tutorials/img/cli_3.png
diff --git a/docs/source/tutorial/img/gui_1.png b/docs/source/tutorials/img/gui_1.png
similarity index 100%
rename from docs/source/tutorial/img/gui_1.png
rename to docs/source/tutorials/img/gui_1.png
diff --git a/docs/source/tutorial/img/gui_2.png b/docs/source/tutorials/img/gui_2.png
similarity index 100%
rename from docs/source/tutorial/img/gui_2.png
rename to docs/source/tutorials/img/gui_2.png
diff --git a/docs/source/tutorial/img/gui_3.png b/docs/source/tutorials/img/gui_3.png
similarity index 100%
rename from docs/source/tutorial/img/gui_3.png
rename to docs/source/tutorials/img/gui_3.png
diff --git a/docs/source/tutorial/img/ota5t.png b/docs/source/tutorials/img/ota5t.png
similarity index 100%
rename from docs/source/tutorial/img/ota5t.png
rename to docs/source/tutorials/img/ota5t.png
diff --git a/docs/source/tutorial/img/ota5t_layout.png b/docs/source/tutorials/img/ota5t_layout.png
similarity index 100%
rename from docs/source/tutorial/img/ota5t_layout.png
rename to docs/source/tutorials/img/ota5t_layout.png
diff --git a/docs/source/tutorial/img/ota5t_sym.png b/docs/source/tutorials/img/ota5t_sym.png
similarity index 100%
rename from docs/source/tutorial/img/ota5t_sym.png
rename to docs/source/tutorials/img/ota5t_sym.png
diff --git a/docs/source/tutorial/img/ota5t_tb.png b/docs/source/tutorials/img/ota5t_tb.png
similarity index 100%
rename from docs/source/tutorial/img/ota5t_tb.png
rename to docs/source/tutorials/img/ota5t_tb.png
diff --git a/docs/source/tutorial/img/ota5t_tmp_tb.png b/docs/source/tutorials/img/ota5t_tmp_tb.png
similarity index 100%
rename from docs/source/tutorial/img/ota5t_tmp_tb.png
rename to docs/source/tutorials/img/ota5t_tmp_tb.png
diff --git a/docs/source/tutorials/index.md b/docs/source/tutorials/index.md
new file mode 100644
index 0000000..f221a1b
--- /dev/null
+++ b/docs/source/tutorials/index.md
@@ -0,0 +1,9 @@
+# Tutorials
+
+```{toctree}
+:glob:
+:maxdepth: 2
+
+ota_5t
+custom_scripts
+```
diff --git a/docs/source/tutorial/index.md b/docs/source/tutorials/ota_5t.md
similarity index 99%
rename from docs/source/tutorial/index.md
rename to docs/source/tutorials/ota_5t.md
index 316e1c4..c54b685 100644
--- a/docs/source/tutorial/index.md
+++ b/docs/source/tutorials/ota_5t.md
@@ -1,4 +1,4 @@
-# Tutorial
+# Tutorial - CACE Setup for a 5T-OTA
 
 This tutorial will guide you step by step through the creation of a simple 5-transistor OTA and the CACE setup for it.
 It is assumed that you have already set up CACE and its dependencies.