diff --git a/neps/search_spaces/hyperparameters/categorical.py b/neps/search_spaces/hyperparameters/categorical.py
index db5566f6..9fa75253 100644
--- a/neps/search_spaces/hyperparameters/categorical.py
+++ b/neps/search_spaces/hyperparameters/categorical.py
@@ -39,6 +39,19 @@ def __init__(
         )
         self.value: None | float | int | str = None
 
+        # Check if 'default' is in 'choices'
+        if default is not None and default not in self.choices:
+            raise ValueError(
+                f"Default value {default} is not in the provided choices {self.choices}"
+            )
+
+        # Check if 'is_fidelity' is a boolean
+        if not isinstance(is_fidelity, bool):
+            raise TypeError(
+                f"Expected 'is_fidelity' to be a boolean, but got type: "
+                f"{type(is_fidelity).__name__}"
+            )
+
     @property
     def id(self):
         return self.value
@@ -46,12 +59,13 @@ def id(self):
     def __eq__(self, other):
         if not isinstance(other, self.__class__):
             return False
-        return (self.choices == other.choices
-                and self.value == other.value
-                and self.is_fidelity == other.is_fidelity
-                and self.default == other.default
-                and self.default_confidence_score == other.default_confidence_score
-                )
+        return (
+            self.choices == other.choices
+            and self.value == other.value
+            and self.is_fidelity == other.is_fidelity
+            and self.default == other.default
+            and self.default_confidence_score == other.default_confidence_score
+        )
 
     def __repr__(self):
         return f"<Categorical, choices: {self.choices}, value: {self.value}>"
diff --git a/neps/search_spaces/hyperparameters/float.py b/neps/search_spaces/hyperparameters/float.py
index 0501ecf7..7dc37042 100644
--- a/neps/search_spaces/hyperparameters/float.py
+++ b/neps/search_spaces/hyperparameters/float.py
@@ -49,17 +49,15 @@ def __init__(
                     f" upper={self.upper}"
                 )
 
-        if not isinstance(log, bool):
-            raise TypeError(
-                f"Expected 'log' to be a boolean, but got type: {type(log).__name__}"
-            )
-
-        if not isinstance(log, bool):
-            raise TypeError(
-                "Expected 'self.log' to be a boolean, but got type: {}".format(
-                    type(log).__name__
+        # Validate 'log' and 'is_fidelity' types to prevent configuration errors
+        # from the YAML input
+        for param, value in {"log": log, "is_fidelity": is_fidelity}.items():
+            if not isinstance(value, bool):
+                raise TypeError(
+                    f"Expected '{param}' to be a boolean, but got type: "
+                    f"{type(value).__name__}"
                 )
-            )
+
         self.log = log
 
         if self.log:
diff --git a/tests/test_yaml_search_space/default_value_not_in_choices_config.yaml b/tests/test_yaml_search_space/default_value_not_in_choices_config.yaml
new file mode 100644
index 00000000..3a1aa4c1
--- /dev/null
+++ b/tests/test_yaml_search_space/default_value_not_in_choices_config.yaml
@@ -0,0 +1,4 @@
+search_space:
+  cat1:
+    choices: ["a", "b", "c"]
+    default: "d"
diff --git a/tests/test_yaml_search_space/not_boolean_type_is_fidelity_cat_config.yaml b/tests/test_yaml_search_space/not_boolean_type_is_fidelity_cat_config.yaml
new file mode 100644
index 00000000..434bd8a1
--- /dev/null
+++ b/tests/test_yaml_search_space/not_boolean_type_is_fidelity_cat_config.yaml
@@ -0,0 +1,5 @@
+search_space:
+  cat1:
+    choices: ["a", "b", "c"]
+    is_fidelity: fals
+    default: "c"
diff --git a/tests/test_yaml_search_space/not_boolean_type_is_fidelity_float_config.yaml b/tests/test_yaml_search_space/not_boolean_type_is_fidelity_float_config.yaml
new file mode 100644
index 00000000..ac527c09
--- /dev/null
+++ b/tests/test_yaml_search_space/not_boolean_type_is_fidelity_float_config.yaml
@@ -0,0 +1,7 @@
+search_space:
+  param_float1:
+    lower: 0.00001
+    upper: 0.1
+    default: 0.001
+    log: false
+    is_fidelity: truee
diff --git a/tests/test_yaml_search_space/not_boolean_type_log_config.yaml b/tests/test_yaml_search_space/not_boolean_type_log_config.yaml
new file mode 100644
index 00000000..5f860194
--- /dev/null
+++ b/tests/test_yaml_search_space/not_boolean_type_log_config.yaml
@@ -0,0 +1,7 @@
+search_space:
+  param_float1:
+    lower: 0.00001
+    upper: 0.1
+    default: 0.001
+    log: falsee
+    is_fidelity: true
diff --git a/tests/test_yaml_search_space/test_search_space.py b/tests/test_yaml_search_space/test_search_space.py
index 23cd0573..961e0713 100644
--- a/tests/test_yaml_search_space/test_search_space.py
+++ b/tests/test_yaml_search_space/test_search_space.py
@@ -109,9 +109,48 @@ def test_yaml_file_including_not_allowed_parameter_keys():
 
 
 @pytest.mark.neps_api
-def test_yaml_file_default_parameter_in_range():
+def test_yaml_file_default_parameter_not_in_range():
     """Test if the default value outside the specified range is
     correctly identified and handled."""
     with pytest.raises(SearchSpaceFromYamlFileError) as excinfo:
         pipeline_space_from_yaml(BASE_PATH + "default_not_in_range_config.yaml")
     assert excinfo.value.exception_type == "ValueError"
+
+
+@pytest.mark.neps_api
+def test_float_log_not_boolean():
+    """Test if an exception is raised when the 'log' attribute is not a boolean."""
+    with pytest.raises(SearchSpaceFromYamlFileError) as excinfo:
+        pipeline_space_from_yaml(BASE_PATH + "not_boolean_type_log_config.yaml")
+    assert excinfo.value.exception_type == "TypeError"
+
+
+@pytest.mark.neps_api
+def test_float_is_fidelity_not_boolean():
+    """Test if an exception is raised when for FloatParameter the 'is_fidelity'
+    attribute is not a boolean."""
+    with pytest.raises(SearchSpaceFromYamlFileError) as excinfo:
+        pipeline_space_from_yaml(
+            BASE_PATH + "not_boolean_type_is_fidelity_float_config.yaml"
+        )
+    assert excinfo.value.exception_type == "TypeError"
+
+
+@pytest.mark.neps_api
+def test_cat_is_fidelity_not_boolean():
+    """Test if an exception is raised when for CategoricalParameter the 'is_fidelity'
+    attribute is not boolean."""
+    with pytest.raises(SearchSpaceFromYamlFileError) as excinfo:
+        pipeline_space_from_yaml(
+            BASE_PATH + "not_boolean_type_is_fidelity_cat_config.yaml"
+        )
+    assert excinfo.value.exception_type == "TypeError"
+
+
+@pytest.mark.neps_api
+def test_categorical_default_value_not_in_choices():
+    """Test if a ValueError is raised when the default value is not in the choices
+    for a CategoricalParameter."""
+    with pytest.raises(SearchSpaceFromYamlFileError) as excinfo:
+        pipeline_space_from_yaml(BASE_PATH + "default_value_not_in_choices_config.yaml")
+    assert excinfo.value.exception_type == "ValueError"