diff --git a/eitprocessing/mixins/equality.py b/eitprocessing/mixins/equality.py
index 58cececaf..c7aa2e7b9 100644
--- a/eitprocessing/mixins/equality.py
+++ b/eitprocessing/mixins/equality.py
@@ -32,21 +32,20 @@ def _array_safe_eq(a, b) -> bool:
     def isequivalent(self, other: Self, raise_: bool = False) -> bool:
         """Test whether the data structure between two objects are equivalent.
 
-        Equivalence in this case means that objects are equal in all respects,
-        except for data content. Generally data loaded from the same source with
-        identical preprocessing will be equivalent.
+        Equivalence, in this case means that objects are compatible e.g. to be
+        merged. Data content can vary, but e.g. the category of data (e.g.
+        airway pressure, flow, tidal volume) and unit, etc., must match.
+
 
         Args:
             other: object that will be compared to self.
-            raise_:
-                if False (default): return `False` if not equivalent;
-                if `True`: raise `EquivalenceError` if not equivalence.
-            checks: Dictionary of bools that will be checked. This dictionary can be
-                defined in each child class individually.
-                Defaults to None, meaning that only `type`s are compared.
+            raise_: sets this method's behavior in case of non-equivalence. If
+                True, an `EquivalenceError` is raised, otherwise `False` is
+                returned.
 
         Raises:
-            EquivalenceError: if `raise_ == True` and the objects are not equivalent.
+            EquivalenceError: if `raise_ == True` and the objects are not
+            equivalent.
 
         Returns:
             bool describing result of equivalence comparison.
@@ -93,9 +92,4 @@ def isequivalent(self, other: Self, raise_: bool = False) -> bool:
 
 
 class EquivalenceError(TypeError, ValueError):
-    """Raised if objects are not equivalent.
-
-    Equivalence in this case means that objects are equal in all respects,
-    except for data content. Generally data loaded from the same source with
-    identical preprocessing will be equivalent.
-    """
+    """Raised if objects are not equivalent."""