diff --git a/ezyrb/database.py b/ezyrb/database.py
index 53bc15b9..7f31ef52 100644
--- a/ezyrb/database.py
+++ b/ezyrb/database.py
@@ -15,10 +15,6 @@ class Database:
 
     :param array_like parameters: the input parameters
     :param array_like snapshots: the input snapshots
-    :param Scale scaler_parameters: the scaler for the parameters. Default
-        is None meaning no scaling.
-    :param Scale scaler_snapshots: the scaler for the snapshots. Default is
-        None meaning no scaling.
     :param array_like space: the input spatial data
 
     :Example:
@@ -46,6 +42,7 @@ def __init__(self, parameters=None, snapshots=None, space=None):
         )
         self._pairs = []
 
+
         if parameters is None and snapshots is None:
             logger.debug("Empty database created")
             return
@@ -149,11 +146,11 @@ def add(self, parameter, snapshot):
         """
         if not isinstance(parameter, Parameter):
             logger.error("Invalid parameter type: %s", type(parameter))
-            raise ValueError
+            raise TypeError(f"Expected a Parameter object, got {type(parameter)}")
 
         if not isinstance(snapshot, Snapshot):
             logger.error("Invalid snapshot type: %s", type(snapshot))
-            raise ValueError
+            raise TypeError(f"Expected a Snapshot object, got {type(snapshot)}")
 
         self._pairs.append((parameter, snapshot))
         logger.debug(
@@ -161,7 +158,7 @@ def add(self, parameter, snapshot):
         )
 
         return self
-
+    
     def split(self, chunks, seed=None):
         """
 
@@ -209,7 +206,7 @@ def split(self, chunks, seed=None):
 
         else:
             logger.error("Invalid chunk type")
-            ValueError
+            raise TypeError(f"Invalid chunk type. Expected a list of integers or floats, but got {type(chunks)}.")
 
         new_database = [Database() for _ in range(len(chunks))]
         for i, chunk in enumerate(chunks):
@@ -235,4 +232,4 @@ def get_snapshot_space(self, index):
         """
         if index < 0 or index >= len(self._pairs):
             raise IndexError("Snapshot index out of range.")
-        return self._pairs[index][1].space
+        return self._pairs[index][1].space
\ No newline at end of file
diff --git a/ezyrb/plugin/scaler.py b/ezyrb/plugin/scaler.py
index 588f54e7..7b6f40a5 100644
--- a/ezyrb/plugin/scaler.py
+++ b/ezyrb/plugin/scaler.py
@@ -10,13 +10,12 @@ class DatabaseScaler(Plugin):
     """
     The plugin to rescale the database of the reduced order model. It uses a
     user defined `scaler`, which has to have implemented the `fit`, `transform`
-    and  `inverse_trasform` methods (i.e. `sklearn` interface), to rescale
+    and  `inverse_transform` methods (i.e. `sklearn` interface), to rescale
     the parameters and/or the snapshots. It can be applied at the full order
-    (`mode='full'`), at the reduced one (`mode='reduced'`) or both of them
-    (`mode='both'`).
+    (`mode='full'`) or at the reduced one (`mode='reduced'`).
 
     :param obj scaler: a generic object which has to have implemented the
-        `fit`, `transform` and  `inverse_trasform` methods (i.e. `sklearn`
+        `fit`, `transform` and  `inverse_transform` methods (i.e. `sklearn`
         interface).
     :param {'full', 'reduced'} mode: define if the rescaling has to be
         applied at the full order ('full') or at the reduced one ('reduced').
@@ -62,11 +61,14 @@ def target(self):
         rtype: str
         """
         return self._target
+    
 
     @target.setter
     def target(self, new_target):
         if new_target not in ["snapshots", "parameters"]:
-            raise ValueError
+            error_msg = f"Invalid target: '{new_target}' must be 'snapshots' or 'parameters'."
+            logger.error(error_msg)
+            raise ValueError(error_msg)
 
         self._target = new_target
 
@@ -82,10 +84,13 @@ def mode(self):
     @mode.setter
     def mode(self, new_mode):
         if new_mode not in ["full", "reduced"]:
-            raise ValueError
+            error_msg = f"Invalid mode: '{new_mode}' must be 'full' or 'reduced'."
+            logger.error(error_msg)
+            raise ValueError(error_msg)
 
         self._mode = new_mode
 
+
     def _select_matrix(self, db):
         """
         Helper function to select the proper matrix to rescale.