diff --git a/aeon/anomaly_detection/base.py b/aeon/anomaly_detection/base.py
index 87ca40aa19..2e333cf755 100644
--- a/aeon/anomaly_detection/base.py
+++ b/aeon/anomaly_detection/base.py
@@ -10,7 +10,7 @@
 import pandas as pd
 
 from aeon.base import BaseSeriesEstimator
-from aeon.base._base_series import VALID_INPUT_TYPES
+from aeon.base._base_series import VALID_SERIES_INPUT_TYPES
 
 
 class BaseAnomalyDetector(BaseSeriesEstimator):
@@ -76,7 +76,7 @@ class BaseAnomalyDetector(BaseSeriesEstimator):
     """
 
     _tags = {
-        "X_inner_type": "np.ndarray",  # One of VALID_INNER_TYPES
+        "X_inner_type": "np.ndarray",  # One of VALID_SERIES_INNER_TYPES
         "fit_is_empty": True,
         "requires_y": False,
     }
@@ -95,14 +95,14 @@ def fit(self, X, y=None, axis=1):
 
         Parameters
         ----------
-        X : one of aeon.base._base_series.VALID_INPUT_TYPES
+        X : one of aeon.base._base_series.VALID_SERIES_INPUT_TYPES
             The time series to fit the model to.
             A valid aeon time series data structure. See
-            aeon.base._base_series.VALID_INPUT_TYPES for aeon supported types.
-        y : one of aeon.base._base_series.VALID_INPUT_TYPES, default=None
+            aeon.base._base_series.VALID_SERIES_INPUT_TYPES for aeon supported types.
+        y : one of aeon.base._base_series.VALID_SERIES_INPUT_TYPES, default=None
             The target values for the time series.
             A valid aeon time series data structure. See
-            aeon.base._base_series.VALID_INPUT_TYPES for aeon supported types.
+            aeon.base._base_series.VALID_SERIES_INPUT_TYPES for aeon supported types.
         axis : int
             The time point axis of the input series if it is 2D. If ``axis==0``, it is
             assumed each column is a time series and each row is a time point. i.e. the
@@ -142,10 +142,10 @@ def predict(self, X, axis=1) -> np.ndarray:
 
         Parameters
         ----------
-        X : one of aeon.base._base_series.VALID_INPUT_TYPES
+        X : one of aeon.base._base_series.VALID_SERIES_INPUT_TYPES
             The time series to fit the model to.
             A valid aeon time series data structure. See
-            aeon.base._base_series.VALID_INPUT_TYPES for aeon supported types.
+            aeon.base._base_series.VALID_SERIES_INPUT_TYPES for aeon supported types.
         axis : int, default=1
             The time point axis of the input series if it is 2D. If ``axis==0``, it is
             assumed each column is a time series and each row is a time point. i.e. the
@@ -173,14 +173,14 @@ def fit_predict(self, X, y=None, axis=1) -> np.ndarray:
 
         Parameters
         ----------
-        X : one of aeon.base._base_series.VALID_INPUT_TYPES
+        X : one of aeon.base._base_series.VALID_SERIES_INPUT_TYPES
             The time series to fit the model to.
             A valid aeon time series data structure. See
             aeon.base._base_series.VALID_INPUT_TYPES for aeon supported types.
-        y : one of aeon.base._base_series.VALID_INPUT_TYPES, default=None
+        y : one of aeon.base._base_series.VALID_SERIES_INPUT_TYPES, default=None
             The target values for the time series.
             A valid aeon time series data structure. See
-            aeon.base._base_series.VALID_INPUT_TYPES for aeon supported types.
+            aeon.base._base_series.VALID_SERIES_INPUT_TYPES for aeon supported types.
         axis : int, default=1
             The time point axis of the input series if it is 2D. If ``axis==0``, it is
             assumed each column is a time series and each row is a time point. i.e. the
@@ -226,7 +226,7 @@ def _fit_predict(self, X, y):
         self._fit(X, y)
         return self._predict(X)
 
-    def _check_y(self, y: VALID_INPUT_TYPES) -> np.ndarray:
+    def _check_y(self, y: VALID_SERIES_INPUT_TYPES) -> np.ndarray:
         # Remind user if y is not required for this estimator on failure
         req_msg = (
             f"{self.__class__.__name__} does not require a y input."
@@ -235,7 +235,8 @@ def _check_y(self, y: VALID_INPUT_TYPES) -> np.ndarray:
         )
         new_y = y
 
-        # must be a valid input type, see VALID_INPUT_TYPES in BaseSeriesEstimator
+        # must be a valid input type, see VALID_SERIES_INPUT_TYPES in
+        # BaseSeriesEstimator
         if isinstance(y, np.ndarray):
             # check valid shape
             if y.ndim > 1:
@@ -284,8 +285,8 @@ def _check_y(self, y: VALID_INPUT_TYPES) -> np.ndarray:
             new_y = y.squeeze().values
         else:
             raise ValueError(
-                f"Error in input type for y: it should be one of {VALID_INPUT_TYPES}, "
-                f"saw {type(y)}"
+                f"Error in input type for y: it should be one of "
+                f"{VALID_SERIES_INPUT_TYPES}, saw {type(y)}"
             )
 
         new_y = new_y.astype(bool)
diff --git a/aeon/anomaly_detection/tests/test_left_stampi.py b/aeon/anomaly_detection/tests/test_left_stampi.py
index 872f6af149..589d163f7b 100644
--- a/aeon/anomaly_detection/tests/test_left_stampi.py
+++ b/aeon/anomaly_detection/tests/test_left_stampi.py
@@ -1,4 +1,4 @@
-"""Tests for the LaftSTAMPi class."""
+"""Tests for the LeftSTAMPi class."""
 
 __maintainer__ = ["ferewi"]
 
diff --git a/aeon/base/_base.py b/aeon/base/_base.py
index 6a9f7dbb70..41ac7010f3 100644
--- a/aeon/base/_base.py
+++ b/aeon/base/_base.py
@@ -4,7 +4,7 @@
 __all__ = ["BaseAeonEstimator"]
 
 import inspect
-from abc import ABC
+from abc import ABC, abstractmethod
 from copy import deepcopy
 
 from sklearn import clone
@@ -12,6 +12,8 @@
 from sklearn.ensemble._base import _set_random_states
 from sklearn.exceptions import NotFittedError
 
+from aeon.utils.validation._dependencies import _check_estimator_deps
+
 
 class BaseAeonEstimator(BaseEstimator, ABC):
     """
@@ -44,12 +46,15 @@ class BaseAeonEstimator(BaseEstimator, ABC):
         "capability:multithreading": False,
     }
 
+    @abstractmethod
     def __init__(self):
         self.is_fitted = False  # flag to indicate if fit has been called
         self._tags_dynamic = dict()  # storage for dynamic tags
 
         super().__init__()
 
+        _check_estimator_deps(self)
+
     def reset(self, keep=None):
         """
         Reset the object to a clean post-init state.
diff --git a/aeon/base/_base_collection.py b/aeon/base/_base_collection.py
index 8319f45d8f..ea3b21ed32 100644
--- a/aeon/base/_base_collection.py
+++ b/aeon/base/_base_collection.py
@@ -1,5 +1,7 @@
 """Base class for estimators that fit collections of time series."""
 
+from abc import abstractmethod
+
 import numpy as np
 
 from aeon.base._base import BaseAeonEstimator
@@ -9,7 +11,6 @@
     resolve_unequal_length_inner_type,
 )
 from aeon.utils.validation import check_n_jobs
-from aeon.utils.validation._dependencies import _check_estimator_deps
 from aeon.utils.validation.collection import (
     get_n_cases,
     get_n_channels,
@@ -22,12 +23,13 @@
 
 
 class BaseCollectionEstimator(BaseAeonEstimator):
-    """Base class for estimators that use collections of time series for ``fit``.
+    """
+    Base class for estimators that use collections of time series for ``fit``.
 
-    Provides functions that are common to estimators which use colections such as
+    Provides functions that are common to estimators which use collections such as
     ``BaseClassifier``, ``BaseRegressor``, ``BaseClusterer``, ``BaseSimilaritySearch``
     and ``BaseCollectionTransformer``. Functionality includes checking and
-    conversion of input to ``fit, predict and predict_proba, where relevant.
+    conversion of input in ``fit``, ``predict`` and ``predict_proba``, where relevant.
 
     It also stores the common default tags used by all the subclasses and meta data
     describing the characteristics of time series passed to ``fit``.
@@ -40,45 +42,54 @@ class BaseCollectionEstimator(BaseAeonEstimator):
         "X_inner_type": "numpy3D",
     }
 
+    @abstractmethod
     def __init__(self):
         self.metadata_ = {}  # metadata/properties of data seen in fit
-        self.fit_time_ = 0  # time elapsed in last fit call
         self._n_jobs = 1
+
         super().__init__()
-        _check_estimator_deps(self)
 
     def _preprocess_collection(self, X, store_metadata=True):
-        """Preprocess input X prior to call to fit.
+        """
+        Preprocess input X prior to calling fit.
 
-        1. Checks the characteristics of X, store metadata, checks self can handle
-            the data
-        2. convert X to X_inner_type
-        3. Check multi-threading against capabilities
+        1. Checks the characteristics of X and that self can handle the data
+        2. Stores metadata about X in self.metadata_ if store_metadata is True
+        3. Converts X to X_inner_type if necessary
 
         Parameters
         ----------
         X : collection
-            See aeon.utils.COLLECTIONS_DATA_TYPES for details
-            on aeon supported data structures.
+            See aeon.utils.COLLECTIONS_DATA_TYPES for details on aeon supported
+            data structures.
         store_metadata : bool, default=True
             Whether to store metadata about X in self.metadata_.
 
         Returns
         -------
-        Data structure of type self.tags["X_inner_type"]
+        X : collection
+            Processed X. A data structure of type self.get_tag("X_inner_type").
+
+        Raises
+        ------
+        ValueError
+            If X is an invalid type or has characteristics that the estimator cannot
+            handle.
 
         See Also
         --------
-        _check_X : function that checks X is valid before conversion.
-        _convert_X : function that converts to inner type.
+        _check_X :
+            Function that checks X is valid before conversion.
+        _convert_X :
+            Function that converts to inner type.
 
         Examples
         --------
-        >>> from aeon.base import BaseCollectionEstimator
-        >>> import numpy as np
-        >>> bce = BaseCollectionEstimator()
-        >>> X = np.random.random(size=(10,20))
-        >>> X2 = bce._preprocess_collection(X)
+        >>> from aeon.testing.mock_estimators import MockClassifier
+        >>> from aeon.testing.data_generation import make_example_2d_numpy_collection
+        >>> clf = MockClassifier()
+        >>> X, _ = make_example_2d_numpy_collection(n_cases=10, n_timepoints=20)
+        >>> X2 = clf._preprocess_collection(X)
         >>> X2.shape
         (10, 1, 20)
         """
@@ -101,24 +112,25 @@ def _preprocess_collection(self, X, store_metadata=True):
         return X
 
     def _check_X(self, X):
-        """Check classifier input X is valid.
+        """
+        Check classifier input X is valid.
 
         Check if the input data is a compatible type, and that this estimator is
-        able to handle the data characteristics. This is done by matching the
-        capabilities of the estimator against the metadata for X for
-        univariate/multivariate, equal length/unequal length and no missing
+        able to handle the data characteristics.
+        This is done by matching the capabilities of the estimator against the metadata
+        for X i.e., univariate/multivariate, equal length/unequal length and no missing
         values/missing values.
 
         Parameters
         ----------
-        X : data structure
-           See aeon.utils.COLLECTIONS_DATA_TYPES for details
-           on aeon supported data structures.
+        X : collection
+           See aeon.utils.COLLECTIONS_DATA_TYPES for details on aeon supported
+           data structures.
 
         Returns
         -------
-        dict
-            Meta data about X, with flags:
+        metadata : dict
+            Metadata about X, with flags:
             metadata["multivariate"] : whether X has more than one channel or not
             metadata["missing_values"] : whether X has missing values or not
             metadata["unequal_length"] : whether X contains unequal length series.
@@ -127,18 +139,28 @@ def _check_X(self, X):
             metadata["n_timepoints"] : number of timepoints in X if equal length, else
                 None
 
+        Raises
+        ------
+        ValueError
+            If X is an invalid type or has characteristics that the estimator cannot
+            handle.
+
         See Also
         --------
-        _convert_X : function that converts X after it has been checked.
+        _convert_X :
+            Function that converts X after it has been checked.
 
         Examples
         --------
-        >>> from aeon.classification.hybrid import HIVECOTEV2
-        >>> import numpy as np
-        >>> X = np.random.random(size=(5,3,10))  # X is equal length, multivariate
-        >>> hc = HIVECOTEV2()
-        >>> meta = hc._check_X(X)  # HC2 can handle this
+        >>> from aeon.testing.mock_estimators import MockClassifierFullTags
+        >>> from aeon.testing.data_generation import make_example_3d_numpy
+        >>> clf = MockClassifierFullTags()
+        >>> X, _ = make_example_3d_numpy(n_channels=3) # X is equal length, multivariate
+        >>> meta = clf._check_X(X) # Classifier can handle this
         """
+        # check if X is a valid type
+        get_type(X)
+
         metadata = self._get_X_metadata(X)
         # Check classifier capabilities for X
         allow_multivariate = self.get_tag("capability:multivariate")
@@ -157,51 +179,54 @@ def _check_X(self, X):
         if problems:
             # construct error message
             problems_and = " and ".join(problems)
-            problems_or = " or ".join(problems)
             msg = (
                 f"Data seen by instance of {type(self).__name__} has {problems_and}, "
-                f"but {type(self).__name__} cannot handle {problems_or}. "
+                f"but {type(self).__name__} cannot handle these characteristics. "
             )
             raise ValueError(msg)
 
         return metadata
 
     def _convert_X(self, X):
-        """Convert X to type defined by tag X_inner_type.
+        """
+        Convert X to type defined by tag X_inner_type.
 
         If the input data is already an allowed type, it is returned unchanged.
 
         If multiple types are allowed by self, then the best one for the type of input
-        data is selected. So, for example, if X_inner_tag is `["np-list", "numpy3D"]`
-        and an `df-list` is passed containing equal length series, will be converted
-        to numpy3D.
+        data is selected. So, for example, if X_inner_tag is ["np-list", "numpy3D"]
+        and an df-list is passed, it will be converted to numpy3D if the series
+        are equal length, and np-list if the series are unequal length.
 
         Parameters
         ----------
-        X : data structure
-            Must be of type aeon.utils.COLLECTIONS_DATA_TYPES.
+        X : collection
+           See aeon.utils.COLLECTIONS_DATA_TYPES for details on aeon supported
+           data structures.
 
         Returns
         -------
-        data structure of type one of self.get_tag("X_inner_type").
+        X : collection
+            Converted X. A data structure of type self.get_tag("X_inner_type").
 
         See Also
         --------
-        _check_X : function that checks X is valid and finds metadata.
+        _check_X :
+            Function that checks X is valid and finds metadata.
 
         Examples
         --------
-        >>> from aeon.classification.hybrid import HIVECOTEV2
-        >>> import numpy as np
+        >>> from aeon.testing.mock_estimators import MockClassifier
+        >>> from aeon.testing.data_generation import make_example_3d_numpy_list
         >>> from aeon.utils.validation import get_type
-        >>> X = [np.random.random(size=(5,10)), np.random.random(size=(5,10))]
+        >>> clf = MockClassifier()
+        >>> X, _ = make_example_3d_numpy_list(max_n_timepoints=8)
         >>> get_type(X)
         'np-list'
-        >>> hc = HIVECOTEV2()
-        >>> hc.get_tag("X_inner_type")
+        >>> clf.get_tag("X_inner_type")
         'numpy3D'
-        >>> X = hc._convert_X(X)
-        >>> get_type(X)
+        >>> X2 = clf._convert_X(X)
+        >>> get_type(X2)
         'numpy3D'
         """
         inner_type = self.get_tag("X_inner_type")
@@ -229,12 +254,18 @@ def _convert_X(self, X):
         return convert_collection(X, inner_type)
 
     def _check_shape(self, X):
-        """Check that the shape of X is consistent with the data seen in fit.
+        """
+        Check that the shape of X is consistent with the data seen in fit.
 
         Parameters
         ----------
         X : data structure
             Must be of type aeon.registry.COLLECTIONS_DATA_TYPES.
+
+        Raises
+        ------
+        ValueError
+            If the shape of X is not consistent with the data seen in fit.
         """
         # if metadata is empty, then we have not seen any data in fit. If the estimator
         # has not been fitted, then _is_fitted should catch this.
diff --git a/aeon/base/_base_series.py b/aeon/base/_base_series.py
index 327114a9c3..6c86940f5b 100644
--- a/aeon/base/_base_series.py
+++ b/aeon/base/_base_series.py
@@ -7,33 +7,35 @@
 __maintainer__ = ["TonyBagnall", "MatthewMiddlehurst"]
 __all__ = ["BaseSeriesEstimator"]
 
+from abc import abstractmethod
 
 import numpy as np
 import pandas as pd
 
 from aeon.base._base import BaseAeonEstimator
-from aeon.utils.validation._dependencies import _check_estimator_deps
 
 # allowed input and internal data types for Series
-VALID_INNER_TYPES = [
+VALID_SERIES_INNER_TYPES = [
     "np.ndarray",
     "pd.DataFrame",
 ]
-VALID_INPUT_TYPES = [pd.DataFrame, pd.Series, np.ndarray]
+VALID_SERIES_INPUT_TYPES = [pd.DataFrame, pd.Series, np.ndarray]
 
 
 class BaseSeriesEstimator(BaseAeonEstimator):
-    """Base class for estimators that use single (possibly multivariate) time series.
+    """
+    Base class for estimators that use single (possibly multivariate) time series.
 
-    Provides functions that are common to BaseSeriesEstimator objects for the checking
-    and conversion of input to fit, predict and transform, where relevant.
+    Provides functions that are common to estimators which use single series such as
+    ``BaseAnomalyDetector``, ``BaseSegmenter``, ``BaseForecaster``,
+    and ``BaseSeriesTransformer``. Functionality includes checking and
+    conversion of input to ``fit``, ``predict`` and ``predict_proba``, where relevant.
 
-    It also stores the common default tags used by all the subclasses and metadata
-    describing the characteristics of time series passed to ``fit`` (or another method
-    if fit does not exist).
+    It also stores the common default tags used by all the subclasses and meta data
+    describing the characteristics of time series passed to ``fit``.
 
-    Input and internal data format (where m is the number of time points and d is the
-    number of channels):
+    Input and internal data format (where ``m`` is the number of time points and ``d``
+    is the number of channels):
         Univariate series:
             np.ndarray, shape ``(m,)``, ``(m, 1)`` or ``(1, m)`` depending on axis.
             This is converted to a 2D np.ndarray internally.
@@ -57,15 +59,45 @@ class BaseSeriesEstimator(BaseAeonEstimator):
     _tags = {
         "capability:univariate": True,
         "capability:multivariate": False,
-        "X_inner_type": "np.ndarray",  # one of VALID_INNER_TYPES
+        "X_inner_type": "np.ndarray",  # one of VALID_SERIES_INNER_TYPES
     }
 
+    @abstractmethod
     def __init__(self, axis):
         self.axis = axis
-        self.metadata_ = {}  # metadata/properties of data seen in fit/predict/transform
+        self.metadata_ = {}  # metadata/properties of data seen in fit
 
         super().__init__()
-        _check_estimator_deps(self)
+
+    def _preprocess_series(self, X, axis, store_metadata):
+        """Preprocess input X prior to call to fit.
+
+        Checks the characteristics of X, store metadata, checks self can handle
+        the data then convert X to X_inner_type
+
+        Parameters
+        ----------
+        X: one of aeon.base._base_series.VALID_SERIES_INPUT_TYPES
+            A valid aeon time series data structure. See
+            aeon.base._base_series.VALID_SERIES_INPUT_TYPES for aeon supported types.
+        axis: int
+            The time point axis of the input series if it is 2D. If ``axis==0``, it is
+            assumed each column is a time series and each row is a time point. i.e. the
+            shape of the data is ``(n_timepoints, n_channels)``. ``axis==1`` indicates
+            the time series are in rows, i.e. the shape of the data is
+            ``(n_channels, n_timepoints)``.
+        store_metadata: bool
+            If True, overwrite metadata with the new metadata from X.
+
+        Returns
+        -------
+        X: one of aeon.base._base_series.VALID_SERIES_INPUT_TYPES
+            Input time series with data structure of type self.get_tag("X_inner_type").
+        """
+        meta = self._check_X(X, axis)
+        if store_metadata:
+            self.metadata_ = meta
+        return self._convert_X(X, axis)
 
     def _check_X(self, X, axis):
         """Check input X is valid.
@@ -77,9 +109,9 @@ def _check_X(self, X, axis):
 
         Parameters
         ----------
-        X: one of aeon.base._base_series.VALID_INPUT_TYPES
+        X: one of aeon.base._base_series.VALID_SERIES_INPUT_TYPES
             A valid aeon time series data structure. See
-            aeon.base._base_series.VALID_INPUT_TYPES for aeon supported types.
+            aeon.base._base_series.VALID_SERIES_INPUT_TYPES for aeon supported types.
         axis: int
             The time point axis of the input series if it is 2D. If ``axis==0``, it is
             assumed each column is a time series and each row is a time point. i.e. the
@@ -113,7 +145,8 @@ def _check_X(self, X, axis):
                 raise ValueError("pd.DataFrame dtype must be numeric")
         else:
             raise ValueError(
-                f"Input type of X should be one of {VALID_INNER_TYPES}, saw {type(X)}"
+                f"Input type of X should be one of {VALID_SERIES_INNER_TYPES}, "
+                f"saw {type(X)}"
             )
 
         metadata = {}
@@ -171,9 +204,9 @@ def _convert_X(self, X, axis):
 
         Parameters
         ----------
-        X: one of aeon.base._base_series.VALID_INPUT_TYPES
+        X: one of aeon.base._base_series.VALID_SERIES_INPUT_TYPES
             A valid aeon time series data structure. See
-            aeon.base._base_series.VALID_INPUT_TYPES for aeon supported types.
+            aeon.base._base_series.VALID_SERIES_INPUT_TYPES for aeon supported types.
         axis: int
             The time point axis of the input series if it is 2D. If ``axis==0``, it is
             assumed each column is a time series and each row is a time point. i.e. the
@@ -183,7 +216,7 @@ def _convert_X(self, X, axis):
 
         Returns
         -------
-        X: one of aeon.base._base_series.VALID_INPUT_TYPES
+        X: one of aeon.base._base_series.VALID_SERIES_INPUT_TYPES
             Input time series with data structure of type self.get_tag("X_inner_type").
         """
         if axis > 1 or axis < 0:
@@ -217,38 +250,3 @@ def _convert_X(self, X, axis):
             X = X[np.newaxis, :] if self.axis == 1 else X[:, np.newaxis]
 
         return X
-
-    def _preprocess_series(self, X, axis, store_metadata):
-        """Preprocess input X prior to call to fit.
-
-        Checks the characteristics of X, store metadata, checks self can handle
-        the data then convert X to X_inner_type
-
-        Parameters
-        ----------
-        X: one of aeon.base._base_series.VALID_INPUT_TYPES
-            A valid aeon time series data structure. See
-            aeon.base._base_series.VALID_INPUT_TYPES for aeon supported types.
-        axis: int or None
-            The time point axis of the input series if it is 2D. If ``axis==0``, it is
-            assumed each column is a time series and each row is a time point. i.e. the
-            shape of the data is ``(n_timepoints, n_channels)``. ``axis==1`` indicates
-            the time series are in rows, i.e. the shape of the data is
-            ``(n_channels, n_timepoints)``.
-            If None, the default class axis is used.
-        store_metadata: bool
-            If True, overwrite metadata with the new metadata from X.
-
-        Returns
-        -------
-        X: one of aeon.base._base_series.VALID_INPUT_TYPES
-            Input time series with data structure of type self.get_tag("X_inner_type").
-        """
-        if axis is None:
-            axis = self.axis
-
-        meta = self._check_X(X, axis)
-        if store_metadata:
-            self.metadata_ = meta
-
-        return self._convert_X(X, axis)
diff --git a/aeon/base/estimators/compose/collection_channel_ensemble.py b/aeon/base/estimators/compose/collection_channel_ensemble.py
index 4164536f19..91ed44ef25 100644
--- a/aeon/base/estimators/compose/collection_channel_ensemble.py
+++ b/aeon/base/estimators/compose/collection_channel_ensemble.py
@@ -6,6 +6,8 @@
 __maintainer__ = ["MatthewMiddlehurst"]
 __all__ = ["BaseCollectionChannelEnsemble"]
 
+from abc import abstractmethod
+
 import numpy as np
 from sklearn.base import BaseEstimator
 from sklearn.utils import check_random_state
@@ -71,6 +73,7 @@ class BaseCollectionChannelEnsemble(ComposableEstimatorMixin, BaseCollectionEsti
     # Used in get_fitted_params
     _fitted_estimators_attr = "ensemble_"
 
+    @abstractmethod
     def __init__(
         self,
         _ensemble,
diff --git a/aeon/base/estimators/compose/collection_ensemble.py b/aeon/base/estimators/compose/collection_ensemble.py
index 1223414ae9..11e9fbc81b 100644
--- a/aeon/base/estimators/compose/collection_ensemble.py
+++ b/aeon/base/estimators/compose/collection_ensemble.py
@@ -6,6 +6,8 @@
 __maintainer__ = ["MatthewMiddlehurst"]
 __all__ = ["BaseCollectionEnsemble"]
 
+from abc import abstractmethod
+
 import numpy as np
 from sklearn.base import BaseEstimator, is_classifier
 from sklearn.metrics import accuracy_score, mean_squared_error
@@ -78,6 +80,7 @@ class BaseCollectionEnsemble(ComposableEstimatorMixin, BaseCollectionEstimator):
     # Used in get_fitted_params
     _fitted_estimators_attr = "ensemble_"
 
+    @abstractmethod
     def __init__(
         self,
         _ensemble,
diff --git a/aeon/base/estimators/compose/collection_pipeline.py b/aeon/base/estimators/compose/collection_pipeline.py
index 48e333d431..1b90c6c411 100644
--- a/aeon/base/estimators/compose/collection_pipeline.py
+++ b/aeon/base/estimators/compose/collection_pipeline.py
@@ -6,6 +6,8 @@
 __maintainer__ = ["MatthewMiddlehurst"]
 __all__ = ["BaseCollectionPipeline"]
 
+from abc import abstractmethod
+
 import numpy as np
 from sklearn.base import BaseEstimator
 from sklearn.utils import check_random_state
@@ -59,6 +61,7 @@ class BaseCollectionPipeline(ComposableEstimatorMixin, BaseCollectionEstimator):
     # Used in get_fitted_params
     _fitted_estimators_attr = "steps_"
 
+    @abstractmethod
     def __init__(self, transformers, _estimator, random_state=None):
         self.transformers = transformers
         self._estimator = _estimator
diff --git a/aeon/base/tests/test_base.py b/aeon/base/tests/test_base.py
index 1caafa0cdf..fcb4ac1907 100644
--- a/aeon/base/tests/test_base.py
+++ b/aeon/base/tests/test_base.py
@@ -234,7 +234,6 @@ def test_get_fitted_params():
     comp_params = composite.get_fitted_params()
 
     expected = {
-        "fit_time_",
         "foo_",
         "classes_",
         "metadata_",
@@ -250,7 +249,6 @@ def test_get_fitted_params():
         {
             "mock_",
             "mock___classes_",
-            "mock___fit_time_",
             "mock___foo_",
             "mock___metadata_",
             "mock___n_classes_",
diff --git a/aeon/base/tests/test_base_collection.py b/aeon/base/tests/test_base_collection.py
index 9fd887eb86..97e2232c66 100644
--- a/aeon/base/tests/test_base_collection.py
+++ b/aeon/base/tests/test_base_collection.py
@@ -6,6 +6,7 @@
 import pytest
 
 from aeon.base import BaseCollectionEstimator
+from aeon.testing.mock_estimators import MockClassifier
 from aeon.testing.testing_data import (
     EQUAL_LENGTH_MULTIVARIATE_CLASSIFICATION,
     EQUAL_LENGTH_UNIVARIATE_CLASSIFICATION,
@@ -83,8 +84,8 @@ def test_get_metadata(data):
 
 def test_check_X():
     """Test if capabilities correctly tested."""
-    dummy1 = BaseCollectionEstimator()
-    dummy2 = BaseCollectionEstimator()
+    dummy1 = MockClassifier()
+    dummy2 = MockClassifier()
     all_tags = {
         "capability:multivariate": True,
         "capability:unequal_length": True,
@@ -99,34 +100,34 @@ def test_check_X():
     # univariate missing values
     X[3][0][6] = np.nan
     assert dummy2._check_X(X)
-    with pytest.raises(ValueError, match=r"cannot handle missing values"):
+    with pytest.raises(ValueError, match=r"has missing values, but"):
         dummy1._check_X(X)
 
     # multivariate equal length
     X = EQUAL_LENGTH_MULTIVARIATE_CLASSIFICATION["numpy3D"]["train"][0].copy()
     assert dummy2._check_X(X)
-    with pytest.raises(ValueError, match=r"cannot handle multivariate"):
+    with pytest.raises(ValueError, match=r"has multivariate series, but"):
         dummy1._check_X(X)
 
     # multivariate missing values
     X[2][1][5] = np.nan
     assert dummy2._check_X(X)
     with pytest.raises(
-        ValueError, match=r"cannot handle missing values or multivariate"
+        ValueError, match=r"has missing values and multivariate series, but"
     ):
         dummy1._check_X(X)
 
     # univariate equal length
     X = UNEQUAL_LENGTH_UNIVARIATE_CLASSIFICATION["np-list"]["train"][0]
     assert dummy2._check_X(X)
-    with pytest.raises(ValueError, match=r"cannot handle unequal length series"):
+    with pytest.raises(ValueError, match=r"has unequal length series, but"):
         dummy1._check_X(X)
 
     # multivariate unequal length
     X = UNEQUAL_LENGTH_MULTIVARIATE_CLASSIFICATION["np-list"]["train"][0]
     assert dummy2._check_X(X)
     with pytest.raises(
-        ValueError, match=r"cannot handle multivariate series or unequal length"
+        ValueError, match=r"has multivariate series and unequal length series, but"
     ):
         dummy1._check_X(X)
 
@@ -141,7 +142,7 @@ def test_check_X():
         dummy1._check_X(X)
 
     # invalid type
-    X = BaseCollectionEstimator()
+    X = MockClassifier()
     with pytest.raises(
         TypeError,
         match="must be of type np.ndarray, pd.DataFrame or list of"
@@ -159,7 +160,7 @@ def test_convert_X(internal_type, data):
     This test runs a subset of these but also checks classifiers with multiple
     internal types.
     """
-    cls = BaseCollectionEstimator()
+    cls = MockClassifier()
 
     # Equal length should default to numpy3D
     X = EQUAL_LENGTH_UNIVARIATE_CLASSIFICATION[data]["train"][0]
@@ -215,7 +216,7 @@ def test_preprocess_collection(data):
     """Test the functionality for preprocessing fit."""
     data = EQUAL_LENGTH_UNIVARIATE_CLASSIFICATION[data]["train"][0]
     data2 = np.random.random(size=(11, 1, 30))
-    cls = BaseCollectionEstimator()
+    cls = MockClassifier()
 
     X = cls._preprocess_collection(data)
     assert cls._n_jobs == 1
@@ -223,13 +224,13 @@ def test_preprocess_collection(data):
     assert get_type(X) == "numpy3D"
 
     tags = {"capability:multithreading": True}
-    cls = BaseCollectionEstimator()
+    cls = MockClassifier()
     cls.set_tags(**tags)
     with pytest.raises(AttributeError, match="self.n_jobs must be set"):
         cls._preprocess_collection(data)
 
     # Test two calls do not overwrite metadata (predict should not reset fit meta)
-    cls = BaseCollectionEstimator()
+    cls = MockClassifier()
     cls._preprocess_collection(data)
     meta = cls.metadata_
     cls._preprocess_collection(data2)
@@ -247,7 +248,7 @@ def test_convert_np_list():
     assert np2[0].shape == (1, 10)
     assert np2[1].shape == (1, 20)
     assert np2[2].shape == (1, 30)
-    dummy1 = BaseCollectionEstimator()
+    dummy1 = MockClassifier()
     x1 = np.random.random(size=(1, 10))
     x2 = np.random.rand(10)
     x3 = np.random.rand(10)
diff --git a/aeon/base/tests/test_base_series.py b/aeon/base/tests/test_base_series.py
index 207b4c678b..5c3a8003c5 100644
--- a/aeon/base/tests/test_base_series.py
+++ b/aeon/base/tests/test_base_series.py
@@ -5,7 +5,7 @@
 import pytest
 from numpy.testing import assert_equal
 
-from aeon.base import BaseSeriesEstimator
+from aeon.testing.mock_estimators._mock_anomaly_detectors import MockAnomalyDetector
 
 UNIVARIATE = {
     "np.ndarray": np.random.random(size=(20)),
@@ -56,7 +56,10 @@
 
 def test_check_X():
     """Test if capabilities correctly tested in _check_X."""
-    dummy = BaseSeriesEstimator(axis=1)
+    dummy = MockAnomalyDetector()
+    dummy.set_tags(
+        **{"capability:multivariate": False, "capability:missing_values": False}
+    )
 
     # check basic univariate input
     meta = dummy._check_X(UNIVARIATE["np.ndarray"], axis=1)
@@ -160,7 +163,7 @@ def test_check_X():
 @pytest.mark.parametrize("input_type", VALID_INPUT_TYPES)
 def test_convert_X_ndarray_inner(input_type):
     """Test _convert_X on with np.ndarray inner type."""
-    dummy = BaseSeriesEstimator(axis=1)
+    dummy = MockAnomalyDetector()
     dummy.set_tags(**{"X_inner_type": "np.ndarray"})
     # test univariate
     X = UNIVARIATE[input_type]
@@ -194,7 +197,7 @@ def test_convert_X_ndarray_inner(input_type):
 @pytest.mark.parametrize("input_type", VALID_INPUT_TYPES)
 def test_convert_X_dataframe_inner(input_type):
     """Test _convert_X on with pd.DataFrame inner type."""
-    dummy = BaseSeriesEstimator(axis=1)
+    dummy = MockAnomalyDetector()
     dummy.set_tags(**{"X_inner_type": "pd.DataFrame"})
     # test univariate
     X = UNIVARIATE[input_type]
@@ -227,7 +230,7 @@ def test_convert_X_dataframe_inner(input_type):
 
 def test_convert_X_invalid():
     """Test _convert_X for invalid inputs."""
-    dummy = BaseSeriesEstimator(axis=1)
+    dummy = MockAnomalyDetector()
 
     with pytest.raises(ValueError, match="Input axis should be 0 or 1, saw 2"):
         dummy._convert_X(UNIVARIATE["np.ndarray"], axis=2)
@@ -243,7 +246,7 @@ def test_convert_X_invalid():
 @pytest.mark.parametrize("inner_type", VALID_INNER_TYPES)
 def test_preprocess_series(input_type, inner_type):
     """Test _preprocess_series for different input and inner types."""
-    dummy = BaseSeriesEstimator(axis=1)
+    dummy = MockAnomalyDetector()
     dummy.set_tags(**{"X_inner_type": inner_type})
     inner_name = inner_type.split(".")[1]
     # test univariate
@@ -287,7 +290,7 @@ def test_preprocess_series(input_type, inner_type):
 
 def test_axis():
     """Test axis property."""
-    dummy = BaseSeriesEstimator(axis=1)
+    dummy = MockAnomalyDetector()
     dummy.set_tags(**{"capability:multivariate": True})
     X = MULTIVARIATE["np.ndarray"]
 
diff --git a/aeon/base/tests/test_compose.py b/aeon/base/tests/test_compose.py
index 55ba965e72..0b6d9b75a0 100644
--- a/aeon/base/tests/test_compose.py
+++ b/aeon/base/tests/test_compose.py
@@ -74,7 +74,6 @@ def test_get_fitted_params():
     expected = {
         "classes_",
         "ensemble_",
-        "fit_time_",
         "metadata_",
         "n_classes_",
         "weights_",
@@ -90,13 +89,11 @@ def test_get_fitted_params():
         {
             "clf1",
             "clf1__classes_",
-            "clf1__fit_time_",
             "clf1__foo_",
             "clf1__metadata_",
             "clf1__n_classes_",
             "clf2",
             "clf2__classes_",
-            "clf2__fit_time_",
             "clf2__foo_",
             "clf2__metadata_",
             "clf2__n_classes_",
diff --git a/aeon/classification/base.py b/aeon/classification/base.py
index ae050e6860..03cbc356d6 100644
--- a/aeon/classification/base.py
+++ b/aeon/classification/base.py
@@ -18,12 +18,9 @@ class name: BaseClassifier
     fitted state inspection - check_is_fitted()
 """
 
-__all__ = [
-    "BaseClassifier",
-]
 __maintainer__ = ["TonyBagnall", "MatthewMiddlehurst"]
+__all__ = ["BaseClassifier"]
 
-import time
 from abc import abstractmethod
 from typing import final
 
@@ -34,7 +31,6 @@ class name: BaseClassifier
 
 from aeon.base import BaseCollectionEstimator
 from aeon.base._base import _clone_estimator
-from aeon.utils.validation._dependencies import _check_estimator_deps
 from aeon.utils.validation.collection import get_n_cases
 from aeon.utils.validation.labels import check_classification_y
 
@@ -65,13 +61,14 @@ class BaseClassifier(BaseCollectionEstimator):
         "capability:contractable": False,
     }
 
+    @abstractmethod
     def __init__(self):
         self.classes_ = []  # classes seen in y, unique labels
         self.n_classes_ = -1  # number of unique classes in y
         self._class_dictionary = {}
         self._estimator_type = "classifier"
+
         super().__init__()
-        _check_estimator_deps(self)
 
     @final
     def fit(self, X, y) -> BaseCollectionEstimator:
@@ -111,13 +108,11 @@ def fit(self, X, y) -> BaseCollectionEstimator:
         Changes state by creating a fitted model that updates attributes
         ending in "_" and sets is_fitted flag to True.
         """
-        start = int(round(time.time() * 1000))
         X, y, single_class = self._fit_setup(X, y)
 
         if not single_class:
             self._fit(X, y)
 
-        self.fit_time_ = int(round(time.time() * 1000)) - start
         # this should happen last
         self.is_fitted = True
         return self
diff --git a/aeon/classification/deep_learning/base.py b/aeon/classification/deep_learning/base.py
index ebee67af7a..2ed56bc0bc 100644
--- a/aeon/classification/deep_learning/base.py
+++ b/aeon/classification/deep_learning/base.py
@@ -47,6 +47,7 @@ class BaseDeepClassifier(BaseClassifier):
         "python_dependencies": "tensorflow",
     }
 
+    @abstractmethod
     def __init__(
         self,
         batch_size=40,
diff --git a/aeon/classification/early_classification/base.py b/aeon/classification/early_classification/base.py
index 5819c53308..e058449ba0 100644
--- a/aeon/classification/early_classification/base.py
+++ b/aeon/classification/early_classification/base.py
@@ -21,12 +21,9 @@ class name: BaseEarlyClassifier
     streaming decision info - state_info attribute
 """
 
-__all__ = [
-    "BaseEarlyClassifier",
-]
-__maintainer__ = []
+__maintainer__ = ["MatthewMiddlehurst"]
+__all__ = ["BaseEarlyClassifier"]
 
-import time
 from abc import abstractmethod
 
 import numpy as np
@@ -49,8 +46,6 @@ class BaseEarlyClassifier(BaseCollectionEstimator):
         Class labels, possibly strings.
     n_classes_ : int
         Number of classes (length of classes_).
-    fit_time_ : int
-        Time (in milliseconds) for fit to run.
     _class_dictionary : dict
         dictionary mapping classes_ onto integers 0...n_classes_-1.
     _n_jobs : int, default=1
@@ -63,12 +58,11 @@ class BaseEarlyClassifier(BaseCollectionEstimator):
         "fit_is_empty": False,
     }
 
+    @abstractmethod
     def __init__(self):
         self.classes_ = []
         self.n_classes_ = 0
-        self.fit_time_ = 0
         self._class_dictionary = {}
-        self._n_jobs = 1
 
         """
         An array containing the state info for each decision in X from update and
@@ -114,11 +108,9 @@ def fit(self, X, y):
         self.reset()
 
         # All of this can move up to BaseCollection
-        start = int(round(time.time() * 1000))
         X = self._preprocess_collection(X)
         y = BaseClassifier._check_y(self, y, self.metadata_["n_cases"])
         self._fit(X, y)
-        self.fit_time_ = int(round(time.time() * 1000)) - start
         # this should happen last
         self.is_fitted = True
         return self
diff --git a/aeon/classification/shapelet_based/_rdst.py b/aeon/classification/shapelet_based/_rdst.py
index 250617d141..cfdbbeb571 100644
--- a/aeon/classification/shapelet_based/_rdst.py
+++ b/aeon/classification/shapelet_based/_rdst.py
@@ -92,8 +92,6 @@ class RDSTClassifier(BaseClassifier):
         The unique class labels in the training set.
     n_classes_ : int
         The number of unique classes in the training set.
-    fit_time_  : int
-        The time (in milliseconds) for ``fit`` to run.
     transformed_data_ : list of shape (n_estimators) of ndarray
         The transformed training dataset for all classifiers. Only saved when
         ``save_transformed_data`` is `True`.
diff --git a/aeon/classification/shapelet_based/_stc.py b/aeon/classification/shapelet_based/_stc.py
index c0ac9df290..9bd80a8cc2 100644
--- a/aeon/classification/shapelet_based/_stc.py
+++ b/aeon/classification/shapelet_based/_stc.py
@@ -77,8 +77,6 @@ class ShapeletTransformClassifier(BaseClassifier):
         The unique class labels in the training set.
     n_classes_ : int
         The number of unique classes in the training set.
-    fit_time_  : int
-        The time (in milliseconds) for ``fit`` to run.
     n_cases_ : int
         The number of train cases in the training set.
     n_channels_ : int
diff --git a/aeon/classification/tests/test_base.py b/aeon/classification/tests/test_base.py
index 353e1eaa7f..e59baa1bf4 100644
--- a/aeon/classification/tests/test_base.py
+++ b/aeon/classification/tests/test_base.py
@@ -139,7 +139,7 @@ def test_unequal_length_input(data):
 
     # Unable to handle unequal length series
     dummy = MockClassifier()
-    with pytest.raises(ValueError, match=r"cannot handle unequal length series"):
+    with pytest.raises(ValueError, match=r"has unequal length series, but"):
         dummy.fit(X, y)
 
     # Able to handle unequal length series
@@ -170,7 +170,7 @@ def test_multivariate_equal_length_input(data):
 
     # Unable to handle multivariate series
     dummy = MockClassifier()
-    with pytest.raises(ValueError, match=r"cannot handle multivariate series"):
+    with pytest.raises(ValueError, match=r"has multivariate series, but"):
         dummy.fit(X, y)
 
     # Able to handle multivariate series
diff --git a/aeon/clustering/base.py b/aeon/clustering/base.py
index 39f216933a..6c8b4344ae 100644
--- a/aeon/clustering/base.py
+++ b/aeon/clustering/base.py
@@ -3,14 +3,12 @@
 __maintainer__ = []
 __all__ = ["BaseClusterer"]
 
-import time
 from abc import abstractmethod
 from typing import final
 
 import numpy as np
 
 from aeon.base import BaseCollectionEstimator
-from aeon.utils.validation._dependencies import _check_estimator_deps
 
 
 class BaseClusterer(BaseCollectionEstimator):
@@ -26,13 +24,13 @@ class BaseClusterer(BaseCollectionEstimator):
         "fit_is_empty": False,
     }
 
+    @abstractmethod
     def __init__(self):
         # required for compatibility with some sklearn interfaces e.g.
         # CalibratedClassifierCV
         self._estimator_type = "clusterer"
 
         super().__init__()
-        _check_estimator_deps(self)
 
     @final
     def fit(self, X, y=None) -> BaseCollectionEstimator:
@@ -56,10 +54,8 @@ def fit(self, X, y=None) -> BaseCollectionEstimator:
             Fitted estimator.
         """
         self.reset()
-        _start_time = int(round(time.time() * 1000))
         X = self._preprocess_collection(X)
         self._fit(X)
-        self.fit_time_ = int(round(time.time() * 1000)) - _start_time
         self.is_fitted = True
         return self
 
diff --git a/aeon/clustering/deep_learning/base.py b/aeon/clustering/deep_learning/base.py
index cedac33546..4a05e8c662 100644
--- a/aeon/clustering/deep_learning/base.py
+++ b/aeon/clustering/deep_learning/base.py
@@ -37,6 +37,7 @@ class BaseDeepClusterer(BaseClusterer):
         "python_dependencies": "tensorflow",
     }
 
+    @abstractmethod
     def __init__(
         self,
         estimator=None,
diff --git a/aeon/clustering/tests/test_base.py b/aeon/clustering/tests/test_base.py
index 8a8fb81b2d..ee765a2f7a 100644
--- a/aeon/clustering/tests/test_base.py
+++ b/aeon/clustering/tests/test_base.py
@@ -43,6 +43,9 @@ def test_correct_input():
 class _TestClusterer(BaseClusterer):
     """Clusterer for testing base class fit/predict/predict_proba."""
 
+    def __init__(self):
+        super().__init__()
+
     def _fit(self, X, y=None):
         """Fit dummy."""
         return self
diff --git a/aeon/networks/base.py b/aeon/networks/base.py
index ec86878dd7..e517894a49 100644
--- a/aeon/networks/base.py
+++ b/aeon/networks/base.py
@@ -13,17 +13,18 @@
 class BaseDeepLearningNetwork(ABC):
     """Abstract base class for deep learning networks."""
 
-    def __init__(self, soft_dependencies="tensorflow", python_version="<3.13"):
-        _check_soft_dependencies(soft_dependencies)
-        _check_python_version(python_version)
-        super().__init__()
-
     _config = {
         "python_dependencies": ["tensorflow"],
         "python_version": "<3.13",
         "structure": "encoder",
     }
 
+    @abstractmethod
+    def __init__(self, soft_dependencies="tensorflow", python_version="<3.13"):
+        _check_soft_dependencies(soft_dependencies)
+        _check_python_version(python_version)
+        super().__init__()
+
     @abstractmethod
     def build_network(self, input_shape, **kwargs):
         """Construct a network and return its input and output layers.
diff --git a/aeon/regression/base.py b/aeon/regression/base.py
index 7f861bfd36..7f9521b5ee 100644
--- a/aeon/regression/base.py
+++ b/aeon/regression/base.py
@@ -18,11 +18,8 @@ class name: BaseRegressor
 """
 
 __maintainer__ = []
-__all__ = [
-    "BaseRegressor",
-]
+__all__ = ["BaseRegressor"]
 
-import time
 from abc import abstractmethod
 from typing import final
 
@@ -45,16 +42,6 @@ class BaseRegressor(BaseCollectionEstimator):
 
     Attributes
     ----------
-    fit_time_ : int
-        Time (in milliseconds) for fit to run.
-    _n_jobs : int
-        Number of threads to use in fit as determined by n_jobs.
-
-    fit_time_ : int
-        Time (in milliseconds) for ``fit`` to run.
-    _n_jobs : int
-        Number of threads to use in estimator methods such as ``fit`` and ``predict``.
-        Determined by the ``n_jobs`` parameter if present.
     _estimator_type : string
         The type of estimator. Required by some ``sklearn`` tools, set to "regressor".
     """
@@ -65,11 +52,8 @@ class BaseRegressor(BaseCollectionEstimator):
         "capability:contractable": False,
     }
 
+    @abstractmethod
     def __init__(self):
-        # reserved attributes written to in fit
-        self.fit_time_ = -1
-        self._n_jobs = 1
-
         # required for compatibility with some sklearn interfaces
         self._estimator_type = "regressor"
 
@@ -113,12 +97,10 @@ def fit(self, X, y) -> BaseCollectionEstimator:
         Changes state by creating a fitted model that updates attributes
         ending in "_" and sets is_fitted flag to True.
         """
-        start = int(round(time.time() * 1000))
         X, y = self._fit_setup(X, y)
 
         self._fit(X, y)
 
-        self.fit_time_ = int(round(time.time() * 1000)) - start
         # this should happen last
         self.is_fitted = True
         return self
diff --git a/aeon/regression/deep_learning/base.py b/aeon/regression/deep_learning/base.py
index ff1ed2a40f..b48e3b2792 100644
--- a/aeon/regression/deep_learning/base.py
+++ b/aeon/regression/deep_learning/base.py
@@ -40,6 +40,7 @@ class BaseDeepRegressor(BaseRegressor):
         "python_dependencies": "tensorflow",
     }
 
+    @abstractmethod
     def __init__(self, batch_size=40, last_file_name="last_model"):
         self.batch_size = batch_size
         self.last_file_name = last_file_name
diff --git a/aeon/regression/shapelet_based/_rdst.py b/aeon/regression/shapelet_based/_rdst.py
index ed02775815..dcc77a3988 100644
--- a/aeon/regression/shapelet_based/_rdst.py
+++ b/aeon/regression/shapelet_based/_rdst.py
@@ -74,8 +74,6 @@ class RDSTRegressor(BaseRegressor):
 
     Attributes
     ----------
-    fit_time_  : int
-        The time (in milliseconds) for ``fit`` to run.
     transformed_data_ : list of shape (n_estimators) of ndarray
         The transformed training dataset for all classifiers. Only saved when
         ``save_transformed_data`` is `True`.
diff --git a/aeon/regression/tests/test_base.py b/aeon/regression/tests/test_base.py
index d06e0bf710..30302de8c7 100644
--- a/aeon/regression/tests/test_base.py
+++ b/aeon/regression/tests/test_base.py
@@ -18,6 +18,9 @@
 class _TestRegressor(BaseRegressor):
     """Dummy regressor for testing base class fit/predict."""
 
+    def __init__(self):
+        super().__init__()
+
     def _fit(self, X, y):
         """Fit dummy."""
         return self
@@ -37,6 +40,9 @@ class _DummyHandlesAllInput(BaseRegressor):
         "X_inner_type": ["np-list", "numpy3D"],
     }
 
+    def __init__(self):
+        super().__init__()
+
     def _fit(self, X, y):
         """Fit dummy."""
         return self
@@ -56,6 +62,9 @@ class _TestHandlesAllInput(BaseRegressor):
         "X_inner_type": ["np-list", "numpy3D"],
     }
 
+    def __init__(self):
+        super().__init__()
+
     def _fit(self, X, y):
         """Fit dummy."""
         return self
@@ -114,7 +123,7 @@ def test_unequal_length_input(data):
         dummy = _TestRegressor()
         X = UNEQUAL_LENGTH_UNIVARIATE_REGRESSION[data]["train"][0]
         y = np.random.random(size=10)
-        with pytest.raises(ValueError, match=r"cannot handle unequal length series"):
+        with pytest.raises(ValueError, match=r"has unequal length series, but"):
             dummy.fit(X, y)
         dummy = _TestHandlesAllInput()
         _assert_fit_predict(dummy, X, y)
diff --git a/aeon/segmentation/_eagglo.py b/aeon/segmentation/_eagglo.py
index 67605b7761..74a585ed4b 100644
--- a/aeon/segmentation/_eagglo.py
+++ b/aeon/segmentation/_eagglo.py
@@ -80,7 +80,7 @@ class EAggloSegmenter(BaseSegmenter):
     """
 
     _tags = {
-        "X_inner_type": "pd.DataFrame",  # One of VALID_INNER_TYPES
+        "X_inner_type": "pd.DataFrame",
         "capability:multivariate": True,
         "fit_is_empty": False,
         "returns_dense": False,
diff --git a/aeon/segmentation/base.py b/aeon/segmentation/base.py
index 6fbcc93100..7a746fd6a3 100644
--- a/aeon/segmentation/base.py
+++ b/aeon/segmentation/base.py
@@ -10,7 +10,7 @@
 import pandas as pd
 
 from aeon.base import BaseSeriesEstimator
-from aeon.base._base_series import VALID_INPUT_TYPES
+from aeon.base._base_series import VALID_SERIES_INPUT_TYPES
 
 
 class BaseSegmenter(BaseSeriesEstimator):
@@ -64,12 +64,13 @@ class BaseSegmenter(BaseSeriesEstimator):
     """
 
     _tags = {
-        "X_inner_type": "np.ndarray",  # One of VALID_INNER_TYPES
+        "X_inner_type": "np.ndarray",  # One of VALID_SERIES_INNER_TYPES
         "fit_is_empty": True,
         "requires_y": False,
         "returns_dense": True,
     }
 
+    @abstractmethod
     def __init__(self, axis, n_segments=2):
         self.n_segments = n_segments
 
@@ -86,9 +87,9 @@ def fit(self, X, y=None, axis=1):
 
         Parameters
         ----------
-        X : One of ``VALID_INPUT_TYPES``
+        X : One of ``VALID_SERIES_INPUT_TYPES``
             Input time series to fit a segmenter.
-        y : One of ``VALID_INPUT_TYPES`` or None, default None
+        y : One of ``VALID_SERIES_INPUT_TYPES`` or None, default None
             Training time series, a labeled 1D series same length as X for supervised
             segmentation.
         axis : int, default = None
@@ -128,7 +129,7 @@ def predict(self, X, axis=1):
 
         Parameters
         ----------
-        X : One of ``VALID_INPUT_TYPES``
+        X : One of ``VALID_SERIES_INPUT_TYPES``
             Input time series
         axis : int, default = None
             Axis along which to segment if passed a multivariate series (2D input)
@@ -168,15 +169,15 @@ def _predict(self, X) -> np.ndarray:
         """Create and return a segmentation of X."""
         ...
 
-    def _check_y(self, y: VALID_INPUT_TYPES):
+    def _check_y(self, y: VALID_SERIES_INPUT_TYPES):
         """Check y specific to segmentation.
 
         y must be a univariate series
         """
-        if type(y) not in VALID_INPUT_TYPES:
+        if type(y) not in VALID_SERIES_INPUT_TYPES:
             raise ValueError(
                 f"Error in input type for y: it should be one of "
-                f"{VALID_INPUT_TYPES}, saw {type(y)}"
+                f"{VALID_SERIES_INPUT_TYPES}, saw {type(y)}"
             )
         if isinstance(y, np.ndarray):
             # Check valid shape
diff --git a/aeon/similarity_search/base.py b/aeon/similarity_search/base.py
index 94febb93da..5b0ce8c555 100644
--- a/aeon/similarity_search/base.py
+++ b/aeon/similarity_search/base.py
@@ -60,6 +60,7 @@ class BaseSimilaritySearch(BaseCollectionEstimator):
         "X_inner_type": ["np-list", "numpy3D"],
     }
 
+    @abstractmethod
     def __init__(
         self,
         distance: str = "euclidean",
diff --git a/aeon/testing/estimator_checking/_yield_anomaly_detection_checks.py b/aeon/testing/estimator_checking/_yield_anomaly_detection_checks.py
index 41eda5a86b..0d94fbc34f 100644
--- a/aeon/testing/estimator_checking/_yield_anomaly_detection_checks.py
+++ b/aeon/testing/estimator_checking/_yield_anomaly_detection_checks.py
@@ -6,7 +6,7 @@
 import pytest
 
 from aeon.base._base import _clone_estimator
-from aeon.base._base_series import VALID_INNER_TYPES
+from aeon.base._base_series import VALID_SERIES_INNER_TYPES
 from aeon.testing.data_generation import (
     make_example_1d_numpy,
     make_example_2d_numpy_series,
@@ -46,7 +46,7 @@ def check_anomaly_detector_overrides_and_tags(estimator_class):
 
     # Test valid tag for X_inner_type
     X_inner_type = estimator_class.get_class_tag(tag_name="X_inner_type")
-    assert X_inner_type in VALID_INNER_TYPES
+    assert X_inner_type in VALID_SERIES_INNER_TYPES
 
     # Must have at least one set to True
     multi = estimator_class.get_class_tag(tag_name="capability:multivariate")
diff --git a/aeon/testing/estimator_checking/_yield_segmentation_checks.py b/aeon/testing/estimator_checking/_yield_segmentation_checks.py
index 898f034f05..6c2c964f5a 100644
--- a/aeon/testing/estimator_checking/_yield_segmentation_checks.py
+++ b/aeon/testing/estimator_checking/_yield_segmentation_checks.py
@@ -6,7 +6,7 @@
 import pytest
 
 from aeon.base._base import _clone_estimator
-from aeon.base._base_series import VALID_INNER_TYPES
+from aeon.base._base_series import VALID_SERIES_INNER_TYPES
 
 
 def _yield_segmentation_checks(estimator_class, estimator_instances, datatypes):
@@ -33,7 +33,7 @@ def check_segmenter_base_functionality(estimator_class):
     assert not fit_is_empty == "_fit" not in estimator_class.__dict__
     # Test valid tag for X_inner_type
     X_inner_type = estimator_class.get_class_tag(tag_name="X_inner_type")
-    assert X_inner_type in VALID_INNER_TYPES
+    assert X_inner_type in VALID_SERIES_INNER_TYPES
     # Must have at least one set to True
     multi = estimator_class.get_class_tag(tag_name="capability:multivariate")
     uni = estimator_class.get_class_tag(tag_name="capability:univariate")
diff --git a/aeon/testing/mock_estimators/_mock_classifiers.py b/aeon/testing/mock_estimators/_mock_classifiers.py
index da766b8e16..bcfcb8162e 100644
--- a/aeon/testing/mock_estimators/_mock_classifiers.py
+++ b/aeon/testing/mock_estimators/_mock_classifiers.py
@@ -12,6 +12,9 @@
 class MockClassifier(BaseClassifier):
     """Mock classifier for testing fit/predict."""
 
+    def __init__(self):
+        super().__init__()
+
     def _fit(self, X, y):
         """Fit dummy."""
         self.foo_ = "bar"
diff --git a/aeon/transformations/base.py b/aeon/transformations/base.py
index f6ccf5b889..7e4998a910 100644
--- a/aeon/transformations/base.py
+++ b/aeon/transformations/base.py
@@ -19,7 +19,10 @@ class BaseTransformer(BaseAeonEstimator):
         "removes_missing_values": False,
     }
 
+    @abstractmethod
     def __init__(self):
+        self._estimator_type = "transformer"
+
         super().__init__()
 
     @abstractmethod
diff --git a/aeon/transformations/collection/_reduce.py b/aeon/transformations/collection/_reduce.py
index ce8bf75d61..00831afe96 100644
--- a/aeon/transformations/collection/_reduce.py
+++ b/aeon/transformations/collection/_reduce.py
@@ -22,6 +22,9 @@ class Tabularizer(BaseCollectionTransformer):
         "capability:multivariate": True,
     }
 
+    def __init__(self):
+        super().__init__()
+
     def _transform(self, X, y=None):
         """Transform collection into tabular dataframe.
 
diff --git a/aeon/transformations/collection/base.py b/aeon/transformations/collection/base.py
index 7b601126a7..e6c774fee9 100644
--- a/aeon/transformations/collection/base.py
+++ b/aeon/transformations/collection/base.py
@@ -44,9 +44,8 @@ class BaseCollectionTransformer(BaseCollectionEstimator, BaseTransformer):
         "removes_unequal_length": False,
     }
 
+    @abstractmethod
     def __init__(self):
-        self._estimator_type = "transformer"
-
         super().__init__()
 
     @final
diff --git a/aeon/transformations/collection/channel_selection/base.py b/aeon/transformations/collection/channel_selection/base.py
index f77afd9764..e9459e3d25 100644
--- a/aeon/transformations/collection/channel_selection/base.py
+++ b/aeon/transformations/collection/channel_selection/base.py
@@ -6,6 +6,7 @@
 
 __maintainer__ = ["TonyBagnall"]
 
+from abc import abstractmethod
 
 from aeon.transformations.collection.base import BaseCollectionTransformer
 
@@ -22,9 +23,8 @@ class BaseChannelSelector(BaseCollectionTransformer):
         List of channels selected in fit.
     """
 
-    def __init__(
-        self,
-    ):
+    @abstractmethod
+    def __init__(self):
         self.channels_selected_ = []
         super().__init__()
 
diff --git a/aeon/transformations/collection/compose/_identity.py b/aeon/transformations/collection/compose/_identity.py
index b9a7652bcc..20c6674b6b 100644
--- a/aeon/transformations/collection/compose/_identity.py
+++ b/aeon/transformations/collection/compose/_identity.py
@@ -16,6 +16,9 @@ class CollectionId(BaseCollectionTransformer):
         "capability:missing_values": True,
     }
 
+    def __init__(self):
+        super().__init__()
+
     def _transform(self, X, y=None):
         return X
 
diff --git a/aeon/transformations/collection/signature_based/_augmentations.py b/aeon/transformations/collection/signature_based/_augmentations.py
index 0bd4525d53..850a40f709 100644
--- a/aeon/transformations/collection/signature_based/_augmentations.py
+++ b/aeon/transformations/collection/signature_based/_augmentations.py
@@ -73,6 +73,9 @@ class _AddTime(BaseCollectionTransformer):
         "fit_is_empty": True,  # is fit empty and can be skipped? Yes = True
     }
 
+    def __init__(self):
+        super().__init__()
+
     def _transform(self, X, y=None):
         data = np.swapaxes(X, 1, 2)
         # Batch and length dim
@@ -98,6 +101,9 @@ class _InvisibilityReset(BaseCollectionTransformer):
         "fit_is_empty": True,  # is fit empty and can be skipped? Yes = True
     }
 
+    def __init__(self):
+        super().__init__()
+
     def _transform(self, X, y=None):
         X = np.swapaxes(X, 1, 2)
 
@@ -138,6 +144,9 @@ class _LeadLag(BaseCollectionTransformer):
         "fit_is_empty": True,
     }
 
+    def __init__(self):
+        super().__init__()
+
     def _transform(self, X, y=None):
         X = np.swapaxes(X, 1, 2)
 
@@ -193,6 +202,9 @@ class _BasePoint(BaseCollectionTransformer):
         "capability:multivariate": True,
     }
 
+    def __init__(self):
+        super().__init__()
+
     def _transform(self, X, y=None):
         X = np.swapaxes(X, 1, 2)
         zero_vec = np.zeros(shape=(X.shape[0], 1, X.shape[2]))
diff --git a/aeon/transformations/series/base.py b/aeon/transformations/series/base.py
index 0a4eb894e4..cdbd7e50c9 100644
--- a/aeon/transformations/series/base.py
+++ b/aeon/transformations/series/base.py
@@ -27,6 +27,7 @@ class BaseSeriesTransformer(BaseSeriesEstimator, BaseTransformer):
         "output_data_type": "Series",
     }
 
+    @abstractmethod
     def __init__(self, axis):
         super().__init__(axis=axis)
 
@@ -294,9 +295,9 @@ def _postprocess_series(self, Xt, axis):
 
         Parameters
         ----------
-        Xt: one of aeon.base._base_series.VALID_INPUT_TYPES
+        Xt: one of aeon.base._base_series.VALID_SERIES_INPUT_TYPES
             A valid aeon time series data structure. See
-            aeon.base._base_series.VALID_INPUT_TYPES for aeon supported types.
+            aeon.base._base_series.VALID_SERIES_INPUT_TYPES for aeon supported types.
             Intended for algorithms which have another series as output.
         axis: int
             The axids of time in the series.
@@ -309,7 +310,7 @@ def _postprocess_series(self, Xt, axis):
 
         Returns
         -------
-        Xt: one of aeon.base._base_series.VALID_INPUT_TYPES
+        Xt: one of aeon.base._base_series.VALID_SERIES_INPUT_TYPES
             New time series input reshaped to match the original input.
         """
         if axis is None:
diff --git a/aeon/utils/_data_types.py b/aeon/utils/_data_types.py
index 0ae6ce9311..0202679fb3 100644
--- a/aeon/utils/_data_types.py
+++ b/aeon/utils/_data_types.py
@@ -8,24 +8,23 @@
 
 Checks of input data are handled in the `aeon.utils.validation` module,
 and conversion  is handled in the `aeon.utils.conversion` module.
-
 """
 
 SERIES_DATA_TYPES = [
     "pd.Series",  # univariate time series of shape (n_timepoints)
-    "pd.DataFrame",  # multivariate time series of shape (n_timepoints, n_channels) by
-    # default or (n_channels, n_timepoints) if set by axis ==1
-    "np.ndarray",  # uni/multivariate time series of shape (n_timepoints, n_channels)
-    # by default or (n_channels, n_timepoints) if set by axis ==1
+    "pd.DataFrame",  # uni/multivariate time series of shape (n_timepoints,
+    # n_channels) by default or (n_channels, n_timepoints) if set by axis == 1
+    "np.ndarray",  # uni/multivariate time series of shape (n_timepoints,
+    # n_channels) by default or (n_channels, n_timepoints) if set by axis ==1
 ]
 
 
 COLLECTIONS_DATA_TYPES = [
     "numpy3D",  # 3D np.ndarray of format (n_cases, n_channels, n_timepoints)
-    "np-list",  # python list of 2D numpy array of length [n_cases],
+    "np-list",  # python list of 2D np.ndarray of length [n_cases],
     # each of shape (n_channels, n_timepoints_i)
-    "df-list",  # python list of 2D pd.DataFrames of length [n_cases], each a of
-    # shape (n_channels, n_timepoints_i)
+    "df-list",  # python list of 2D pd.DataFrames of length [n_cases], each
+    # of shape (n_channels, n_timepoints_i)
     "numpy2D",  # 2D np.ndarray of shape (n_cases, n_timepoints)
     "pd-wide",  # 2D pd.DataFrame of shape (n_cases, n_timepoints)
     "pd-multiindex",  # pd.DataFrame with multi-index,
diff --git a/aeon/utils/conversion/_convert_collection.py b/aeon/utils/conversion/_convert_collection.py
index 9c3a3eb33c..e41ed0c8a2 100644
--- a/aeon/utils/conversion/_convert_collection.py
+++ b/aeon/utils/conversion/_convert_collection.py
@@ -440,7 +440,7 @@ def resolve_unequal_length_inner_type(inner_types: Sequence[str]) -> str:
         return "pd-multiindex"
     raise ValueError(
         f"Error, no valid inner types for unequal series in {inner_types} "
-        f"must be np-list or pd-multiindex"
+        f"must be np-list, df-list or pd-multiindex"
     )
 
 
diff --git a/examples/base/series_estimator.ipynb b/examples/base/series_estimator.ipynb
index ecfab1e302..57e719cd78 100644
--- a/examples/base/series_estimator.ipynb
+++ b/examples/base/series_estimator.ipynb
@@ -38,11 +38,12 @@
     "import numpy as np\n",
     "import pandas as pd\n",
     "\n",
-    "from aeon.base import BaseSeriesEstimator\n",
+    "from aeon.testing.mock_estimators._mock_anomaly_detectors import MockAnomalyDetector\n",
     "\n",
-    "# We use the abstract base class for example purposes, regular classes will not\n",
-    "# have a class axis parameter.\n",
-    "bs = BaseSeriesEstimator(axis=0)"
+    "# We use a mock anomaly detector for example purposes, It has a default axis of 1,\n",
+    "# but we will change it to 0 for these examples\n",
+    "bs = MockAnomalyDetector()\n",
+    "bs.axis = 0"
    ],
    "outputs": [],
    "execution_count": 14