DOC improve estimator set_params documentation
@@ -370,9 +370,10 @@ While when `deep=False`, the output will be::
my_extra_param -> random
subestimator -> LogisticRegression()
-The ``set_params`` on the other hand takes as input a dict of the form
-``'parameter': value`` and sets the parameter of the estimator using this dict.
-Return value must be estimator itself.
+On the other hand, ``set_params`` takes the parameters of ``__init__``
+as keyword arguments, unpacks them into a dict of the form
+``'parameter': value`` and sets the parameters of the estimator using this dict.
+Return value must be the estimator itself.
While the ``get_params`` mechanism is not essential (see :ref:`cloning` below),
the ``set_params`` function is necessary as it is used to set parameters during
