From ff54b4f9e0983ea81e83a4dce49d53caeb2fd74d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Tue, 8 Jul 2025 12:26:56 +0200
Subject: [PATCH 01/23] sign

---
 extension_templates/experiments.py            |  4 +
 src/hyperactive/base/_experiment.py           | 39 ++++++++-
 .../experiment/integrations/sklearn_cv.py     | 84 +++++++++++++++++++
 src/hyperactive/opt/_adapters/_gfo.py         |  2 +-
 src/hyperactive/tests/test_all_objects.py     | 12 ++-
 5 files changed, 137 insertions(+), 4 deletions(-)

diff --git a/extension_templates/experiments.py b/extension_templates/experiments.py
index e5efe1fe..cc009266 100644
--- a/extension_templates/experiments.py
+++ b/extension_templates/experiments.py
@@ -77,6 +77,10 @@ class MyExperiment(BaseExperiment):
         # valid values: "random", "deterministic"
         # if "deterministic", two calls of score must result in the same value
         #
+        "property:higher_or_lower_is_better": "lower",
+        # valid values: "higher", "lower", "mixed"
+        # whether higher or lower scores are better
+        #
         # --------------
         # packaging info
         # --------------
diff --git a/src/hyperactive/base/_experiment.py b/src/hyperactive/base/_experiment.py
index 22036e63..269cf8fc 100644
--- a/src/hyperactive/base/_experiment.py
+++ b/src/hyperactive/base/_experiment.py
@@ -14,14 +14,16 @@ class BaseExperiment(BaseObject):
         "property:randomness": "random",  # random or deterministic
         # if deterministic, two calls of score will result in the same value
         # random = two calls may result in different values; same as "stochastic"
+        "property:higher_or_lower_is_better": "lower",  # "higher", "lower", "mixed"
+        # whether higher or lower scores are better
     }
 
     def __init__(self):
         super().__init__()
 
     def __call__(self, **kwargs):
-        """Score parameters, with kwargs call."""
-        score, _ = self.score(kwargs)
+        """Score parameters, with kwargs call. Same as cost call."""
+        score, _ = self.cost(kwargs)
         return score
 
     @property
@@ -86,3 +88,36 @@ def _score(self, params):
             Additional metadata about the search.
         """
         raise NotImplementedError
+
+    def cost(self, params):
+        """Score the parameters - with sign such that lower is better.
+
+        Same as ``score`` call except for the sign.
+
+        If the tag ``property:higher_or_lower_is_better`` is set to
+        ``"higher"``, the result is ``-self.score(params)``.
+
+        If the tag is set to ``"lower"``, the result is
+        identical to ``self.score(params)``.
+
+        Parameters
+        ----------
+        params : dict with string keys
+            Parameters to score.
+
+        Returns
+        -------
+        float
+            The score of the parameters.
+        dict
+            Additional metadata about the search.
+        """
+        hib = self.get_tag("property:higher_or_lower_is_better", "lower")
+        if hib == "higher":
+            sign = -1
+        elif hib == "lower":
+            sign = 1
+
+        score_res = self.score(params)
+
+        return sign * score_res[0], score_res[1]
diff --git a/src/hyperactive/experiment/integrations/sklearn_cv.py b/src/hyperactive/experiment/integrations/sklearn_cv.py
index bf60db00..788297d4 100644
--- a/src/hyperactive/experiment/integrations/sklearn_cv.py
+++ b/src/hyperactive/experiment/integrations/sklearn_cv.py
@@ -110,6 +110,13 @@ def __init__(self, estimator, X, y, scoring=None, cv=None):
                 self._scoring = make_scorer(scoring)
         self.scorer_ = self._scoring
 
+        # Set the sign of the scoring function
+        if hasattr(self._scoring, "_score"):
+            score_func = self._scoring._score_func
+            _sign = _guess_sign_of_sklmetric(score_func)
+            _sign_str = "higher" if _sign == 1 else "lower"
+            self.set_tags(**{"property:higher_or_lower_is_better": _sign_str})
+
     def _paramnames(self):
         """Return the parameter names of the search.
 
@@ -235,3 +242,80 @@ def _get_score_params(self):
         score_params_regress = {"C": 1.0, "kernel": "linear"}
         score_params_defaults = {"C": 1.0, "kernel": "linear"}
         return [score_params_classif, score_params_regress, score_params_defaults]
+
+
+def _guess_sign_of_sklmetric(scorer):
+    """Guess the sign of a sklearn metric scorer.
+
+    Parameters
+    ----------
+    scorer : callable
+        The sklearn metric scorer to guess the sign for.
+
+    Returns
+    -------
+    int
+        1 if higher scores are better, -1 if lower scores are better.
+    """
+    HIGHER_IS_BETTER = {
+        # Classification
+        "accuracy_score": True,
+        "auc": True,
+        "average_precision_score": True,
+        "balanced_accuracy_score": True,
+        "brier_score_loss": False,
+        "class_likelihood_ratios": False,
+        "cohen_kappa_score": True,
+        "d2_log_loss_score": True,
+        "dcg_score": True,
+        "f1_score": True,
+        "fbeta_score": True,
+        "hamming_loss": False,
+        "hinge_loss": False,
+        "jaccard_score": True,
+        "log_loss": False,
+        "matthews_corrcoef": True,
+        "ndcg_score": True,
+        "precision_score": True,
+        "recall_score": True,
+        "roc_auc_score": True,
+        "top_k_accuracy_score": True,
+        "zero_one_loss": False,
+
+        # Regression
+        "d2_absolute_error_score": True,
+        "d2_pinball_score": True,
+        "d2_tweedie_score": True,
+        "explained_variance_score": True,
+        "max_error": False,
+        "mean_absolute_error": False,
+        "mean_absolute_percentage_error": False,
+        "mean_gamma_deviance": False,
+        "mean_pinball_loss": False,
+        "mean_poisson_deviance": False,
+        "mean_squared_error": False,
+        "mean_squared_log_error": False,
+        "mean_tweedie_deviance": False,
+        "median_absolute_error": False,
+        "r2_score": True,
+        "root_mean_squared_error": False,
+        "root_mean_squared_log_error": False,
+    }
+
+    scorer_name = getattr(scorer, "__name__", None)
+
+    if hasattr(scorer, "greater_is_better"):
+        return 1 if scorer.greater_is_better else -1
+    elif scorer_name in HIGHER_IS_BETTER:
+        return 1 if HIGHER_IS_BETTER[scorer_name] else -1
+    elif scorer_name.endswith("_score"):
+        # If the scorer name ends with "_score", we assume higher is better
+        return 1
+    elif scorer_name.endswith("_loss") or scorer_name.endswith("_deviance"):
+        # If the scorer name ends with "_loss", we assume lower is better
+        return -1
+    elif scorer_name.endswith("_error"):
+        return -1
+    else:
+        # If we cannot determine the sign, we assume lower is better
+        return -1
diff --git a/src/hyperactive/opt/_adapters/_gfo.py b/src/hyperactive/opt/_adapters/_gfo.py
index c2bae3d9..8e78a9c3 100644
--- a/src/hyperactive/opt/_adapters/_gfo.py
+++ b/src/hyperactive/opt/_adapters/_gfo.py
@@ -133,7 +133,7 @@ def _run(self, experiment, **search_config):
 
         with StdoutMute(active=not self.verbose):
             gfopt.search(
-                objective_function=experiment.score,
+                objective_function=experiment.cost,
                 n_iter=n_iter,
                 max_time=max_time,
             )
diff --git a/src/hyperactive/tests/test_all_objects.py b/src/hyperactive/tests/test_all_objects.py
index b5b4955f..b503a63d 100644
--- a/src/hyperactive/tests/test_all_objects.py
+++ b/src/hyperactive/tests/test_all_objects.py
@@ -45,6 +45,7 @@ class PackageConfig:
         "maintainers",
         # experiments
         "property:randomness",
+        "property:higher_or_lower_is_better",
         # optimizers
         "info:name",  # str
         "info:local_vs_global",  # "local", "mixed", "global"
@@ -184,10 +185,19 @@ def test_score_function(self, object_class):
             assert isinstance(score, float), f"Score is not a float: {score}"
             assert isinstance(metadata, dict), f"Metadata is not a dict: {metadata}"
 
+            cost_res = inst.cost(obj)
+            msg = f"Cost function did not return a length two tuple: {res}"
+            assert isinstance(cost_res, tuple) and len(cost_res) == 2, msg
+            c_score, c_metadata = cost_res
+            assert isinstance(c_score, float), f"Score is not a float: {c_score}"
+            assert isinstance(c_metadata, dict), f"Metadata is not a dict: {c_metadata}"
+
+            assert abs(c_score) == score
+
             call_sc = inst(**obj)
             assert isinstance(call_sc, float), f"Score is not a float: {call_sc}"
             if inst.get_tag("property:randomness") == "deterministic":
-                assert score == call_sc, f"Score does not match: {score} != {call_sc}"
+                assert c_score == call_sc, f"Score does not match: {score} != {call_sc}"
 
 
 class OptimizerFixtureGenerator(BaseFixtureGenerator):

From fa418e42b6c8ac245d42457d18be71e68d91e338 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Tue, 8 Jul 2025 12:36:29 +0200
Subject: [PATCH 02/23] Update test_all_objects.py

---
 src/hyperactive/tests/test_all_objects.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/hyperactive/tests/test_all_objects.py b/src/hyperactive/tests/test_all_objects.py
index b503a63d..431c9039 100644
--- a/src/hyperactive/tests/test_all_objects.py
+++ b/src/hyperactive/tests/test_all_objects.py
@@ -197,7 +197,8 @@ def test_score_function(self, object_class):
             call_sc = inst(**obj)
             assert isinstance(call_sc, float), f"Score is not a float: {call_sc}"
             if inst.get_tag("property:randomness") == "deterministic":
-                assert c_score == call_sc, f"Score does not match: {score} != {call_sc}"
+                msg = f"Score does not match: {c_score} != {call_sc}"
+                assert c_score == call_sc, msg
 
 
 class OptimizerFixtureGenerator(BaseFixtureGenerator):

From 81ea22ce25be14b05603d693498eb30c530b0874 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Tue, 8 Jul 2025 12:38:24 +0200
Subject: [PATCH 03/23] Update test_all_objects.py

---
 src/hyperactive/tests/test_all_objects.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/hyperactive/tests/test_all_objects.py b/src/hyperactive/tests/test_all_objects.py
index 431c9039..125ae1d4 100644
--- a/src/hyperactive/tests/test_all_objects.py
+++ b/src/hyperactive/tests/test_all_objects.py
@@ -192,7 +192,9 @@ def test_score_function(self, object_class):
             assert isinstance(c_score, float), f"Score is not a float: {c_score}"
             assert isinstance(c_metadata, dict), f"Metadata is not a dict: {c_metadata}"
 
-            assert abs(c_score) == score
+            if inst.get_tag("property:randomness") == "deterministic":
+                msg = f"Score and cost calls do not match: |{c_score}| != |{score}|"
+                assert abs(c_score) == score, msg
 
             call_sc = inst(**obj)
             assert isinstance(call_sc, float), f"Score is not a float: {call_sc}"

From 7c023db4881a89adf76505891317b7fb992f9b96 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Tue, 8 Jul 2025 12:53:13 +0200
Subject: [PATCH 04/23] Update test_all_objects.py

---
 src/hyperactive/tests/test_all_objects.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hyperactive/tests/test_all_objects.py b/src/hyperactive/tests/test_all_objects.py
index 125ae1d4..900991e5 100644
--- a/src/hyperactive/tests/test_all_objects.py
+++ b/src/hyperactive/tests/test_all_objects.py
@@ -194,7 +194,7 @@ def test_score_function(self, object_class):
 
             if inst.get_tag("property:randomness") == "deterministic":
                 msg = f"Score and cost calls do not match: |{c_score}| != |{score}|"
-                assert abs(c_score) == score, msg
+                assert abs(c_score) == abs(score), msg
 
             call_sc = inst(**obj)
             assert isinstance(call_sc, float), f"Score is not a float: {call_sc}"

From c161afefbdd7cc902b7ed0916e587fcddba508cd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 17:42:17 +0200
Subject: [PATCH 05/23] flip sign

---
 extension_templates/experiments.py            | 14 +++----
 src/hyperactive/base/_experiment.py           | 38 +++++++++----------
 .../experiment/integrations/sklearn_cv.py     |  8 ++--
 src/hyperactive/experiment/toy/_ackley.py     | 19 +++++++++-
 src/hyperactive/experiment/toy/_parabola.py   | 19 +++++++++-
 src/hyperactive/experiment/toy/_sphere.py     | 19 +++++++++-
 6 files changed, 84 insertions(+), 33 deletions(-)

diff --git a/extension_templates/experiments.py b/extension_templates/experiments.py
index cc009266..8c4f0502 100644
--- a/extension_templates/experiments.py
+++ b/extension_templates/experiments.py
@@ -75,11 +75,11 @@ class MyExperiment(BaseExperiment):
         #
         "property:randomness": "random",
         # valid values: "random", "deterministic"
-        # if "deterministic", two calls of score must result in the same value
+        # if "deterministic", two calls of "evaluate" must result in the same value
         #
         "property:higher_or_lower_is_better": "lower",
         # valid values: "higher", "lower", "mixed"
-        # whether higher or lower scores are better
+        # whether higher or lower returns of "evaluate" are better
         #
         # --------------
         # packaging info
@@ -151,25 +151,25 @@ def _paramnames(self):
         return ["score_param1", "score_param2"]
 
     # todo: implement this, mandatory
-    def _score(self, params):
-        """Score the parameters.
+    def _evaluate(self, params):
+        """Evaluate the parameters.
 
         Parameters
         ----------
         params : dict with string keys
-            Parameters to score.
+            Parameters to evaluate.
 
         Returns
         -------
         float
-            The score of the parameters.
+            The value of the parameters as per evaluation.
         dict
             Additional metadata about the search.
         """
         # params is a dictionary with keys being paramnames or subset thereof
         # IMPORTANT: avoid side effects to params!
         #
-        # the method may work if only a subste of the parameters in paramnames is passed
+        # the method may work if only a subset of the parameters in paramnames is passed
         # but this is not necessary
         value = 42  # must be numpy.float64
         metadata = {"some": "metadata"}  # can be any dict
diff --git a/src/hyperactive/base/_experiment.py b/src/hyperactive/base/_experiment.py
index 269cf8fc..c1b870cf 100644
--- a/src/hyperactive/base/_experiment.py
+++ b/src/hyperactive/base/_experiment.py
@@ -14,7 +14,7 @@ class BaseExperiment(BaseObject):
         "property:randomness": "random",  # random or deterministic
         # if deterministic, two calls of score will result in the same value
         # random = two calls may result in different values; same as "stochastic"
-        "property:higher_or_lower_is_better": "lower",  # "higher", "lower", "mixed"
+        "property:higher_or_lower_is_better": "higher",  # "higher", "lower", "mixed"
         # whether higher or lower scores are better
     }
 
@@ -22,8 +22,8 @@ def __init__(self):
         super().__init__()
 
     def __call__(self, **kwargs):
-        """Score parameters, with kwargs call. Same as cost call."""
-        score, _ = self.cost(kwargs)
+        """Score parameters, with kwargs call. Same as score call."""
+        score, _ = self.score(kwargs)
         return score
 
     @property
@@ -50,55 +50,55 @@ def _paramnames(self):
         """
         raise NotImplementedError
 
-    def score(self, params):
-        """Score the parameters.
+    def evaluate(self, params):
+        """Evaluate the parameters.
 
         Parameters
         ----------
         params : dict with string keys
-            Parameters to score.
+            Parameters to evaluate.
 
         Returns
         -------
         float
-            The score of the parameters.
+            The value of the parameters as per evaluation.
         dict
             Additional metadata about the search.
         """
         paramnames = self.paramnames()
         if not set(params.keys()) <= set(paramnames):
             raise ValueError("Parameters do not match.")
-        res, metadata = self._score(params)
+        res, metadata = self._evaluate(params)
         res = np.float64(res)
         return res, metadata
 
-    def _score(self, params):
-        """Score the parameters.
+    def _evaluate(self, params):
+        """Evaluate the parameters.
 
         Parameters
         ----------
         params : dict with string keys
-            Parameters to score.
+            Parameters to evaluate.
 
         Returns
         -------
         float
-            The score of the parameters.
+            The value of the parameters as per evaluation.
         dict
             Additional metadata about the search.
         """
         raise NotImplementedError
 
-    def cost(self, params):
-        """Score the parameters - with sign such that lower is better.
+    def score(self, params):
+        """Score the parameters - with sign such that higher is always better.
 
-        Same as ``score`` call except for the sign.
+        Same as ``evaluate`` call except for the sign chosen so that higher is better.
 
         If the tag ``property:higher_or_lower_is_better`` is set to
-        ``"higher"``, the result is ``-self.score(params)``.
+        ``"lower"``, the result is ``-self.evaluate(params)``.
 
-        If the tag is set to ``"lower"``, the result is
-        identical to ``self.score(params)``.
+        If the tag is set to ``"higher"``, the result is
+        identical to ``self.evaluate(params)``.
 
         Parameters
         ----------
@@ -118,6 +118,6 @@ def cost(self, params):
         elif hib == "lower":
             sign = 1
 
-        score_res = self.score(params)
+        score_res = self.evaluate(params)
 
         return sign * score_res[0], score_res[1]
diff --git a/src/hyperactive/experiment/integrations/sklearn_cv.py b/src/hyperactive/experiment/integrations/sklearn_cv.py
index 788297d4..14650c95 100644
--- a/src/hyperactive/experiment/integrations/sklearn_cv.py
+++ b/src/hyperactive/experiment/integrations/sklearn_cv.py
@@ -127,18 +127,18 @@ def _paramnames(self):
         """
         return list(self.estimator.get_params().keys())
 
-    def _score(self, params):
-        """Score the parameters.
+    def _evaluate(self, params):
+        """Evaluate the parameters.
 
         Parameters
         ----------
         params : dict with string keys
-            Parameters to score.
+            Parameters to evaluate.
 
         Returns
         -------
         float
-            The score of the parameters.
+            The value of the parameters as per evaluation.
         dict
             Additional metadata about the search.
         """
diff --git a/src/hyperactive/experiment/toy/_ackley.py b/src/hyperactive/experiment/toy/_ackley.py
index 40d14e15..6981f5f3 100644
--- a/src/hyperactive/experiment/toy/_ackley.py
+++ b/src/hyperactive/experiment/toy/_ackley.py
@@ -49,6 +49,9 @@ class Ackley(BaseExperiment):
         "property:randomness": "deterministic",  # random or deterministic
         # if deterministic, two calls of score will result in the same value
         # random = two calls may result in different values; same as "stochastic"
+        "property:higher_or_lower_is_better": "lower",
+        # values are "higher", "lower", "mixed"
+        # whether higher or lower scores are better
     }
 
     def __init__(self, a=20, b=0.2, c=2 * np.pi, d=2):
@@ -61,7 +64,21 @@ def __init__(self, a=20, b=0.2, c=2 * np.pi, d=2):
     def _paramnames(self):
         return [f"x{i}" for i in range(self.d)]
 
-    def _score(self, params):
+    def _evaluate(self, params):
+        """Evaluate the parameters.
+
+        Parameters
+        ----------
+        params : dict with string keys
+            Parameters to evaluate.
+
+        Returns
+        -------
+        float
+            The value of the parameters as per evaluation.
+        dict
+            Additional metadata about the search.
+        """
         x_vec = np.array([params[f"x{i}"] for i in range(self.d)])
 
         loss1 = -self.a * np.exp(-self.b * np.sqrt(np.sum(x_vec**2) / self.d))
diff --git a/src/hyperactive/experiment/toy/_parabola.py b/src/hyperactive/experiment/toy/_parabola.py
index 40893524..b090d8f5 100644
--- a/src/hyperactive/experiment/toy/_parabola.py
+++ b/src/hyperactive/experiment/toy/_parabola.py
@@ -43,6 +43,9 @@ class Parabola(BaseExperiment):
         "property:randomness": "deterministic",  # random or deterministic
         # if deterministic, two calls of score will result in the same value
         # random = two calls may result in different values; same as "stochastic"
+        "property:higher_or_lower_is_better": "lower",
+        # values are "higher", "lower", "mixed"
+        # whether higher or lower scores are better
     }
 
     def __init__(self, a=1.0, b=0.0, c=0.0):
@@ -54,7 +57,21 @@ def __init__(self, a=1.0, b=0.0, c=0.0):
     def _paramnames(self):
         return ["x", "y"]
 
-    def _score(self, params):
+    def _evaluate(self, params):
+        """Evaluate the parameters.
+
+        Parameters
+        ----------
+        params : dict with string keys
+            Parameters to evaluate.
+
+        Returns
+        -------
+        float
+            The value of the parameters as per evaluation.
+        dict
+            Additional metadata about the search.
+        """
         x = params["x"]
         y = params["y"]
 
diff --git a/src/hyperactive/experiment/toy/_sphere.py b/src/hyperactive/experiment/toy/_sphere.py
index afb1493a..7d405278 100644
--- a/src/hyperactive/experiment/toy/_sphere.py
+++ b/src/hyperactive/experiment/toy/_sphere.py
@@ -50,6 +50,9 @@ class Sphere(BaseExperiment):
         "property:randomness": "deterministic",  # random or deterministic
         # if deterministic, two calls of score will result in the same value
         # random = two calls may result in different values; same as "stochastic"
+        "property:higher_or_lower_is_better": "lower",
+        # values are "higher", "lower", "mixed"
+        # whether higher or lower scores are better
     }
 
     def __init__(self, const=0, n_dim=2):
@@ -61,7 +64,21 @@ def __init__(self, const=0, n_dim=2):
     def _paramnames(self):
         return [f"x{i}" for i in range(self.n_dim)]
 
-    def _score(self, params):
+    def _evaluate(self, params):
+        """Evaluate the parameters.
+
+        Parameters
+        ----------
+        params : dict with string keys
+            Parameters to evaluate.
+
+        Returns
+        -------
+        float
+            The value of the parameters as per evaluation.
+        dict
+            Additional metadata about the search.
+        """
         params_vec = np.array([params[f"x{i}"] for i in range(self.n_dim)])
         return np.sum(params_vec ** 2) + self.const, {}
 

From 7e99afd23c7c0bd65c7411c85f13bb2c78806227 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 17:43:43 +0200
Subject: [PATCH 06/23] tests

---
 src/hyperactive/opt/_adapters/_gfo.py     |  2 +-
 src/hyperactive/tests/test_all_objects.py | 20 ++++++++++----------
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/src/hyperactive/opt/_adapters/_gfo.py b/src/hyperactive/opt/_adapters/_gfo.py
index 8e78a9c3..c2bae3d9 100644
--- a/src/hyperactive/opt/_adapters/_gfo.py
+++ b/src/hyperactive/opt/_adapters/_gfo.py
@@ -133,7 +133,7 @@ def _run(self, experiment, **search_config):
 
         with StdoutMute(active=not self.verbose):
             gfopt.search(
-                objective_function=experiment.cost,
+                objective_function=experiment.score,
                 n_iter=n_iter,
                 max_time=max_time,
             )
diff --git a/src/hyperactive/tests/test_all_objects.py b/src/hyperactive/tests/test_all_objects.py
index 900991e5..0cc5612c 100644
--- a/src/hyperactive/tests/test_all_objects.py
+++ b/src/hyperactive/tests/test_all_objects.py
@@ -185,22 +185,22 @@ def test_score_function(self, object_class):
             assert isinstance(score, float), f"Score is not a float: {score}"
             assert isinstance(metadata, dict), f"Metadata is not a dict: {metadata}"
 
-            cost_res = inst.cost(obj)
-            msg = f"Cost function did not return a length two tuple: {res}"
-            assert isinstance(cost_res, tuple) and len(cost_res) == 2, msg
-            c_score, c_metadata = cost_res
-            assert isinstance(c_score, float), f"Score is not a float: {c_score}"
-            assert isinstance(c_metadata, dict), f"Metadata is not a dict: {c_metadata}"
+            eval_res = inst.evaluate(obj)
+            msg = f"eval function did not return a length two tuple: {res}"
+            assert isinstance(eval_res, tuple) and len(eval_res) == 2, msg
+            e_score, e_metadata = eval_res
+            assert isinstance(e_score, float), f"Score is not a float: {e_score}"
+            assert isinstance(e_metadata, dict), f"Metadata is not a dict: {e_metadata}"
 
             if inst.get_tag("property:randomness") == "deterministic":
-                msg = f"Score and cost calls do not match: |{c_score}| != |{score}|"
-                assert abs(c_score) == abs(score), msg
+                msg = f"Score and eval calls do not match: |{e_score}| != |{score}|"
+                assert abs(e_score) == abs(score), msg
 
             call_sc = inst(**obj)
             assert isinstance(call_sc, float), f"Score is not a float: {call_sc}"
             if inst.get_tag("property:randomness") == "deterministic":
-                msg = f"Score does not match: {c_score} != {call_sc}"
-                assert c_score == call_sc, msg
+                msg = f"Score does not match: {e_score} != {call_sc}"
+                assert e_score == call_sc, msg
 
 
 class OptimizerFixtureGenerator(BaseFixtureGenerator):

From 02b8440b67bd7a0f9c647a578aca937d6b1b9383 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 17:46:17 +0200
Subject: [PATCH 07/23] Update _optimizer.py

---
 src/hyperactive/base/_optimizer.py | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/hyperactive/base/_optimizer.py b/src/hyperactive/base/_optimizer.py
index 8a3cca54..bf0c8128 100644
--- a/src/hyperactive/base/_optimizer.py
+++ b/src/hyperactive/base/_optimizer.py
@@ -54,10 +54,21 @@ def get_experiment(self):
     def run(self):
         """Run the optimization search process.
 
+        The optimization searches for the maximizer of the experiment's
+        ``score`` method.
+
+        Depending on the tag ``property:higher_or_lower_is_better`` being
+        set to ``higher`` or ``lower``, the ``run`` method will search for:
+
+        * the minimizer of the ``evaluate`` method if the tag is ``lower``
+        * the maximizer of the ``evaluate`` method if the tag is ``higher``
+
         Returns
         -------
         best_params : dict
             The best parameters found during the optimization process.
+            The dict ``best_params`` can be used in ``experiment.score`` or
+            ``experiment.evaluate`` directly.
         """
         experiment = self.get_experiment()
         search_config = self.get_search_config()

From f959d7c554a85d9bdad4dfd72076dbe7ea786857 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 17:52:17 +0200
Subject: [PATCH 08/23] docs

---
 extension_templates/optimizers.py  | 10 ++++++++--
 src/hyperactive/base/_optimizer.py |  4 ++--
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/extension_templates/optimizers.py b/extension_templates/optimizers.py
index 2e62a7c0..4fee0a3d 100644
--- a/extension_templates/optimizers.py
+++ b/extension_templates/optimizers.py
@@ -142,7 +142,8 @@ def _paramnames(self):
         return ["score_param1", "score_param2"]
 
     # optional: implement this to prepare arguments for _run
-    # the default is all parameters passed to __init__, except ex
+    # the default is all parameters passed to __init__, minus the experiment
+    # the result of this is passed to _run as search_config
     def get_search_config(self):
         """Get the search configuration.
 
@@ -153,12 +154,15 @@ def get_search_config(self):
         """
         # the default
         search_config = super().get_search_config()
+        # example of adding a new parameter to the search config
+        # this is optional, but can be useful for clean separation or API interfacing
         search_config["one_more_param"] = 42
+        # this return is available in _run as search_config
         return search_config
 
     # todo: implement this, mandatory
     def _run(self, experiment, **search_config):
-        """Run the optimization search process.
+        """Run the optimization search process to maximize the experiment's score.
 
         Parameters
         ----------
@@ -173,6 +177,8 @@ def _run(self, experiment, **search_config):
             The best parameters found during the search.
             Must have keys a subset or identical to experiment.paramnames().
         """
+        # important: the search logic should *maximize* the experiment's score
+        # this is the main method to implement, it should return the best parameters
         best_params = {"write_some_logic_to_get": "best_params"}
         return best_params
 
diff --git a/src/hyperactive/base/_optimizer.py b/src/hyperactive/base/_optimizer.py
index bf0c8128..dba7eea1 100644
--- a/src/hyperactive/base/_optimizer.py
+++ b/src/hyperactive/base/_optimizer.py
@@ -52,9 +52,9 @@ def get_experiment(self):
         return self._experiment
 
     def run(self):
-        """Run the optimization search process.
+        """Run the optimization search process to maximize the experiment's score.
 
-        The optimization searches for the maximizer of the experiment's
+        The optimization searches for a maximizer of the experiment's
         ``score`` method.
 
         Depending on the tag ``property:higher_or_lower_is_better`` being

From fc29310f934b0c193cd3e7cbc8722f5a0be82fd2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 18:01:51 +0200
Subject: [PATCH 09/23] fix error of sign

---
 src/hyperactive/base/_experiment.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/hyperactive/base/_experiment.py b/src/hyperactive/base/_experiment.py
index c1b870cf..fb85bc04 100644
--- a/src/hyperactive/base/_experiment.py
+++ b/src/hyperactive/base/_experiment.py
@@ -114,9 +114,9 @@ def score(self, params):
         """
         hib = self.get_tag("property:higher_or_lower_is_better", "lower")
         if hib == "higher":
-            sign = -1
-        elif hib == "lower":
             sign = 1
+        elif hib == "lower":
+            sign = -1
 
         score_res = self.evaluate(params)
 

From cdf0db3df6f6aeab2bc16aa303148da937eb9a2f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 18:02:50 +0200
Subject: [PATCH 10/23] Update _experiment.py

---
 src/hyperactive/base/_experiment.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/hyperactive/base/_experiment.py b/src/hyperactive/base/_experiment.py
index fb85bc04..db5d2aeb 100644
--- a/src/hyperactive/base/_experiment.py
+++ b/src/hyperactive/base/_experiment.py
@@ -118,6 +118,8 @@ def score(self, params):
         elif hib == "lower":
             sign = -1
 
-        score_res = self.evaluate(params)
+        eval_res = self.evaluate(params)
+        value = eval_res[0]
+        metadata = eval_res[1]
 
-        return sign * score_res[0], score_res[1]
+        return sign * value, metadata

From ef64b58d97d45f65810200b2ac8ad9f8c577cf46 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 18:09:01 +0200
Subject: [PATCH 11/23] Update test_all_objects.py

---
 src/hyperactive/tests/test_all_objects.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hyperactive/tests/test_all_objects.py b/src/hyperactive/tests/test_all_objects.py
index 0cc5612c..c0842f66 100644
--- a/src/hyperactive/tests/test_all_objects.py
+++ b/src/hyperactive/tests/test_all_objects.py
@@ -199,7 +199,7 @@ def test_score_function(self, object_class):
             call_sc = inst(**obj)
             assert isinstance(call_sc, float), f"Score is not a float: {call_sc}"
             if inst.get_tag("property:randomness") == "deterministic":
-                msg = f"Score does not match: {e_score} != {call_sc}"
+                msg = f"Score does not match: {res} != {call_sc}"
                 assert e_score == call_sc, msg
 
 

From 2ca896859f97af990a81899e5d03e2d94cf85690 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 18:10:51 +0200
Subject: [PATCH 12/23] Update test_all_objects.py

---
 src/hyperactive/tests/test_all_objects.py | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/hyperactive/tests/test_all_objects.py b/src/hyperactive/tests/test_all_objects.py
index c0842f66..f452bc0a 100644
--- a/src/hyperactive/tests/test_all_objects.py
+++ b/src/hyperactive/tests/test_all_objects.py
@@ -192,16 +192,24 @@ def test_score_function(self, object_class):
             assert isinstance(e_score, float), f"Score is not a float: {e_score}"
             assert isinstance(e_metadata, dict), f"Metadata is not a dict: {e_metadata}"
 
-            if inst.get_tag("property:randomness") == "deterministic":
+            det_tag = inst.get_tag("property:randomness", "random")
+
+            if det_tag == "deterministic":
                 msg = f"Score and eval calls do not match: |{e_score}| != |{score}|"
                 assert abs(e_score) == abs(score), msg
 
             call_sc = inst(**obj)
             assert isinstance(call_sc, float), f"Score is not a float: {call_sc}"
-            if inst.get_tag("property:randomness") == "deterministic":
+            if det_tag == "deterministic":
                 msg = f"Score does not match: {res} != {call_sc}"
                 assert e_score == call_sc, msg
 
+            sign_tag = inst.get_tag("property:higher_or_lower_is_better", "lower")
+            if sign_tag == "higher" and det_tag == "deterministic":
+                assert e_score == res
+            elif sign_tag == "lower" and det_tag == "deterministic":
+                assert e_score == -res
+
 
 class OptimizerFixtureGenerator(BaseFixtureGenerator):
     """Fixture generator for optimizers.

From 3488f808b65f46b8abac36bef61d5c43aae39194 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 18:11:02 +0200
Subject: [PATCH 13/23] Update test_all_objects.py

---
 src/hyperactive/tests/test_all_objects.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hyperactive/tests/test_all_objects.py b/src/hyperactive/tests/test_all_objects.py
index f452bc0a..61ff9603 100644
--- a/src/hyperactive/tests/test_all_objects.py
+++ b/src/hyperactive/tests/test_all_objects.py
@@ -204,7 +204,7 @@ def test_score_function(self, object_class):
                 msg = f"Score does not match: {res} != {call_sc}"
                 assert e_score == call_sc, msg
 
-            sign_tag = inst.get_tag("property:higher_or_lower_is_better", "lower")
+            sign_tag = inst.get_tag("property:higher_or_lower_is_better", "higher")
             if sign_tag == "higher" and det_tag == "deterministic":
                 assert e_score == res
             elif sign_tag == "lower" and det_tag == "deterministic":

From 851af4a62e4ec9108e641cb5f01c88091590953f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 18:23:25 +0200
Subject: [PATCH 14/23] Update test_all_objects.py

---
 src/hyperactive/tests/test_all_objects.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/hyperactive/tests/test_all_objects.py b/src/hyperactive/tests/test_all_objects.py
index 61ff9603..126b070c 100644
--- a/src/hyperactive/tests/test_all_objects.py
+++ b/src/hyperactive/tests/test_all_objects.py
@@ -201,14 +201,14 @@ def test_score_function(self, object_class):
             call_sc = inst(**obj)
             assert isinstance(call_sc, float), f"Score is not a float: {call_sc}"
             if det_tag == "deterministic":
-                msg = f"Score does not match: {res} != {call_sc}"
+                msg = f"Score does not match: {e_score} != {call_sc}"
                 assert e_score == call_sc, msg
 
             sign_tag = inst.get_tag("property:higher_or_lower_is_better", "higher")
             if sign_tag == "higher" and det_tag == "deterministic":
-                assert e_score == res
+                assert score == e_score
             elif sign_tag == "lower" and det_tag == "deterministic":
-                assert e_score == -res
+                assert score == -e_score
 
 
 class OptimizerFixtureGenerator(BaseFixtureGenerator):

From 60a6d81375d954a7f4a4d8d59dcfea2b26e2a5e9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 18:42:11 +0200
Subject: [PATCH 15/23] negative

---
 src/hyperactive/base/_experiment.py           |  12 ++
 .../experiment/compose/__init__.py            |   7 +
 .../experiment/compose/_negative.py           | 130 ++++++++++++++++++
 3 files changed, 149 insertions(+)
 create mode 100644 src/hyperactive/experiment/compose/__init__.py
 create mode 100644 src/hyperactive/experiment/compose/_negative.py

diff --git a/src/hyperactive/base/_experiment.py b/src/hyperactive/base/_experiment.py
index db5d2aeb..46491587 100644
--- a/src/hyperactive/base/_experiment.py
+++ b/src/hyperactive/base/_experiment.py
@@ -30,6 +30,18 @@ def __call__(self, **kwargs):
     def __name__(self):
         return type(self).__name__
 
+    def __neg__(self):
+        """Negate the experiment.
+
+        Returns
+        -------
+        BaseExperiment
+            A new experiment with negated score.
+        """
+        from hyperactive.experiment.compose import Negative
+        # return a new experiment with negated score
+        return Negative(self)
+
     def paramnames(self):
         """Return the parameter names of the search.
 
diff --git a/src/hyperactive/experiment/compose/__init__.py b/src/hyperactive/experiment/compose/__init__.py
new file mode 100644
index 00000000..6adbd893
--- /dev/null
+++ b/src/hyperactive/experiment/compose/__init__.py
@@ -0,0 +1,7 @@
+"""Composition classes for experiments."""
+# copyright: hyperactive developers, MIT License (see LICENSE file)
+
+
+from hyperactive.experiment.compose._negative import Negative
+
+__all__ = ["Negative"]
diff --git a/src/hyperactive/experiment/compose/_negative.py b/src/hyperactive/experiment/compose/_negative.py
new file mode 100644
index 00000000..fe01e0cc
--- /dev/null
+++ b/src/hyperactive/experiment/compose/_negative.py
@@ -0,0 +1,130 @@
+"""Negation of experiment."""
+# copyright: hyperactive developers, MIT License (see LICENSE file)
+
+from hyperactive.base import BaseExperiment
+
+
+class Negative(BaseExperiment):
+    """Negative of an experiment - flips the sign of the score.
+
+    Can also be invoked by using the unary negation operator ``-``
+    on an experiment instance, e.g., ``-experiment``.
+
+    Useful in baselines or composite objectives.
+
+    This composition class is configurable and allows to negate separately:
+
+    * the sign of the score returned by the experiment,
+    * the orientation of the optimization (minimization vs maximization).
+
+    By default, both the score and the orientation are flipped,
+    i.e., an experiment to maximize a function ``f(x)`` becomes an
+    experiment to minimize ``-f(x)``, and vice versa.
+
+    Parameters
+    ----------
+    experiment : BaseExperiment
+        The experiment to be negated. It should be an instance of ``BaseExperiment``.
+    flip_score : bool, default=True
+        Whether to flip the score of the experiment. If True, the score will be
+        negated, i.e., the score will be ``-f`` where ``f`` is the original score.
+    flip_orientation : bool, default=True
+        Whether to flip the orientation of the optimization. If True,
+        minimization and maximization will be swapped in the experiment.
+
+    Example
+    -------
+    >>> import numpy as np
+    >>> from hyperactive.toy.ackley import Ackley
+    >>> from hyperactive.experiment.compose import Negative
+    >>>
+    >>> ackley_exp = Ackley(a=20, b=0.2, c=2 * np.pi, d=2)
+    >>> neg_ackley_exp = Negative(ackley_exp)
+    """
+
+    def __init__(self, experiment, flip_score=True, flip_orientation=True):
+        self.experiment = experiment
+        self.flip_score = flip_score
+        self.flip_orientation = flip_orientation
+
+        super().__init__()
+
+        if self.flip_orientation:
+            current_tag = self.get_tag("property:higher_or_lower_is_better", "mixed")
+            if current_tag == "higher":
+                self.set_tags(**{"property:higher_or_lower_is_better": "lower"})
+            elif current_tag == "lower":
+                self.set_tags(**{"property:higher_or_lower_is_better": "higher"})
+
+    def _paramnames(self):
+        """Return the parameter names of the search.
+
+        Returns
+        -------
+        list of str
+            The parameter names of the search parameters.
+        """
+        return self.experiment.paramnames()
+
+    def _evaluate(self, params):
+        """Evaluate the parameters.
+
+        Parameters
+        ----------
+        params : dict with string keys
+            Parameters to evaluate.
+
+        Returns
+        -------
+        float
+            The value of the parameters as per evaluation.
+        dict
+            Additional metadata about the search.
+        """
+        value, metadata = self.experiment.evaluate(params)
+        if self.flip_score:
+            value = -value
+        return value, metadata
+
+    @classmethod
+    def get_test_params(cls, parameter_set="default"):
+        """Return testing parameter settings for the skbase object.
+
+        ``get_test_params`` is a unified interface point to store
+        parameter settings for testing purposes. This function is also
+        used in ``create_test_instance`` and ``create_test_instances_and_names``
+        to construct test instances.
+
+        ``get_test_params`` should return a single ``dict``, or a ``list`` of ``dict``.
+
+        Each ``dict`` is a parameter configuration for testing,
+        and can be used to construct an "interesting" test instance.
+        A call to ``cls(**params)`` should
+        be valid for all dictionaries ``params`` in the return of ``get_test_params``.
+
+        The ``get_test_params`` need not return fixed lists of dictionaries,
+        it can also return dynamic or stochastic parameter settings.
+
+        Parameters
+        ----------
+        parameter_set : str, default="default"
+            Name of the set of test parameters to return, for use in tests. If no
+            special parameters are defined for a value, will return `"default"` set.
+
+        Returns
+        -------
+        params : dict or list of dict, default = {}
+            Parameters to create testing instances of the class
+            Each dict are parameters to construct an "interesting" test instance, i.e.,
+            `MyClass(**params)` or `MyClass(**params[i])` creates a valid test instance.
+            `create_test_instance` uses the first (or only) dictionary in `params`
+        """
+        from hyperactive.toy.ackley import Ackley
+
+        ackley_exp = Ackley(a=20, b=0.2, c=2, d=2)
+
+        params0 = {"experiment": ackley_exp}
+        params1 = {"experiment": ackley_exp, "flip_orientation": False}
+        params2 = {"experiment": ackley_exp, "flip_score": False}
+
+        return [params0, params1, params2]

From 3f6c8c8c2242fc72117625bc24b5ed32afb83a80 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 18:42:21 +0200
Subject: [PATCH 16/23] Update _negative.py

---
 src/hyperactive/experiment/compose/_negative.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/hyperactive/experiment/compose/_negative.py b/src/hyperactive/experiment/compose/_negative.py
index fe01e0cc..762c7c62 100644
--- a/src/hyperactive/experiment/compose/_negative.py
+++ b/src/hyperactive/experiment/compose/_negative.py
@@ -25,9 +25,11 @@ class Negative(BaseExperiment):
     ----------
     experiment : BaseExperiment
         The experiment to be negated. It should be an instance of ``BaseExperiment``.
+
     flip_score : bool, default=True
         Whether to flip the score of the experiment. If True, the score will be
         negated, i.e., the score will be ``-f`` where ``f`` is the original score.
+
     flip_orientation : bool, default=True
         Whether to flip the orientation of the optimization. If True,
         minimization and maximization will be swapped in the experiment.

From 18c7faace0ec44c6043dd1938eaf79724823ebac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 18:45:11 +0200
Subject: [PATCH 17/23] Update test_all_objects.py

---
 src/hyperactive/tests/test_all_objects.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/hyperactive/tests/test_all_objects.py b/src/hyperactive/tests/test_all_objects.py
index 126b070c..3635b3bb 100644
--- a/src/hyperactive/tests/test_all_objects.py
+++ b/src/hyperactive/tests/test_all_objects.py
@@ -201,8 +201,8 @@ def test_score_function(self, object_class):
             call_sc = inst(**obj)
             assert isinstance(call_sc, float), f"Score is not a float: {call_sc}"
             if det_tag == "deterministic":
-                msg = f"Score does not match: {e_score} != {call_sc}"
-                assert e_score == call_sc, msg
+                msg = f"Score does not match: {score} != {call_sc}"
+                assert score == call_sc, msg
 
             sign_tag = inst.get_tag("property:higher_or_lower_is_better", "higher")
             if sign_tag == "higher" and det_tag == "deterministic":

From 33a619ed51cc238f4a1b600fc4d92a4d7e1df551 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 19:03:47 +0200
Subject: [PATCH 18/23] Update _negative.py

---
 src/hyperactive/experiment/compose/_negative.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hyperactive/experiment/compose/_negative.py b/src/hyperactive/experiment/compose/_negative.py
index 762c7c62..2614a0de 100644
--- a/src/hyperactive/experiment/compose/_negative.py
+++ b/src/hyperactive/experiment/compose/_negative.py
@@ -121,7 +121,7 @@ def get_test_params(cls, parameter_set="default"):
             `MyClass(**params)` or `MyClass(**params[i])` creates a valid test instance.
             `create_test_instance` uses the first (or only) dictionary in `params`
         """
-        from hyperactive.toy.ackley import Ackley
+        from hyperactive.experiment.toy import Ackley
 
         ackley_exp = Ackley(a=20, b=0.2, c=2, d=2)
 

From 2433a853d70d2f510fcab48b73d83d5ed14470e7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 19:36:22 +0200
Subject: [PATCH 19/23] Update experiments.py

---
 extension_templates/experiments.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/extension_templates/experiments.py b/extension_templates/experiments.py
index 8c4f0502..efed25fe 100644
--- a/extension_templates/experiments.py
+++ b/extension_templates/experiments.py
@@ -245,7 +245,7 @@ def _get_score_params(self):
             The parameters to be used for scoring.
         """
         # dict keys should be same as paramnames return
-        # or subset, only if _score allows for subsets of parameters
+        # or subset, only if _evaluate allows for subsets of parameters
         score_params1 = {"score_param1": "foo", "score_param2": "bar"}
         score_params2 = {"score_param1": "baz", "score_param2": "qux"}
         return [score_params1, score_params2]

From 247f7473c6b1a3aa9b317b4ea1aa33df802e230d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 19:36:44 +0200
Subject: [PATCH 20/23] Update experiments.py

---
 extension_templates/experiments.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/extension_templates/experiments.py b/extension_templates/experiments.py
index efed25fe..aaa48b32 100644
--- a/extension_templates/experiments.py
+++ b/extension_templates/experiments.py
@@ -237,7 +237,7 @@ def _get_score_params(self):
         """Return settings for testing the score function. Used in tests only.
 
         Returns a list, the i-th element corresponds to self.get_test_params()[i].
-        It should be a valid call for self.score.
+        It should be a valid call for self.evaluate.
 
         Returns
         -------

From 8a2a14ecc078d41eb5317891046b90dceb8d8a53 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 19:38:56 +0200
Subject: [PATCH 21/23] docstr

---
 extension_templates/experiments.py                    | 7 ++++---
 src/hyperactive/experiment/integrations/sklearn_cv.py | 7 ++++---
 src/hyperactive/experiment/toy/_ackley.py             | 7 ++++---
 src/hyperactive/experiment/toy/_parabola.py           | 7 ++++---
 src/hyperactive/experiment/toy/_sphere.py             | 7 ++++---
 5 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/extension_templates/experiments.py b/extension_templates/experiments.py
index aaa48b32..d3a5496a 100644
--- a/extension_templates/experiments.py
+++ b/extension_templates/experiments.py
@@ -234,10 +234,11 @@ def get_test_params(cls, parameter_set="default"):
 
     @classmethod
     def _get_score_params(self):
-        """Return settings for testing the score function. Used in tests only.
+        """Return settings for testing score/evaluate functions. Used in tests only.
 
-        Returns a list, the i-th element corresponds to self.get_test_params()[i].
-        It should be a valid call for self.evaluate.
+        Returns a list, the i-th element should be valid arguments for
+        self.evaluate and self.score, of an instance constructed with
+        self.get_test_params()[i].
 
         Returns
         -------
diff --git a/src/hyperactive/experiment/integrations/sklearn_cv.py b/src/hyperactive/experiment/integrations/sklearn_cv.py
index 14650c95..fa32f7fe 100644
--- a/src/hyperactive/experiment/integrations/sklearn_cv.py
+++ b/src/hyperactive/experiment/integrations/sklearn_cv.py
@@ -228,10 +228,11 @@ def get_test_params(cls, parameter_set="default"):
 
     @classmethod
     def _get_score_params(self):
-        """Return settings for testing the score function. Used in tests only.
+        """Return settings for testing score/evaluate functions. Used in tests only.
 
-        Returns a list, the i-th element corresponds to self.get_test_params()[i].
-        It should be a valid call for self.score.
+        Returns a list, the i-th element should be valid arguments for
+        self.evaluate and self.score, of an instance constructed with
+        self.get_test_params()[i].
 
         Returns
         -------
diff --git a/src/hyperactive/experiment/toy/_ackley.py b/src/hyperactive/experiment/toy/_ackley.py
index 6981f5f3..6eb67733 100644
--- a/src/hyperactive/experiment/toy/_ackley.py
+++ b/src/hyperactive/experiment/toy/_ackley.py
@@ -127,10 +127,11 @@ def get_test_params(cls, parameter_set="default"):
 
     @classmethod
     def _get_score_params(self):
-        """Return settings for testing the score function. Used in tests only.
+        """Return settings for testing score/evaluate functions. Used in tests only.
 
-        Returns a list, the i-th element corresponds to self.get_test_params()[i].
-        It should be a valid call for self.score.
+        Returns a list, the i-th element should be valid arguments for
+        self.evaluate and self.score, of an instance constructed with
+        self.get_test_params()[i].
 
         Returns
         -------
diff --git a/src/hyperactive/experiment/toy/_parabola.py b/src/hyperactive/experiment/toy/_parabola.py
index b090d8f5..d9672f96 100644
--- a/src/hyperactive/experiment/toy/_parabola.py
+++ b/src/hyperactive/experiment/toy/_parabola.py
@@ -79,10 +79,11 @@ def _evaluate(self, params):
 
     @classmethod
     def _get_score_params(self):
-        """Return settings for testing the score function. Used in tests only.
+        """Return settings for testing score/evaluate functions. Used in tests only.
 
-        Returns a list, the i-th element corresponds to self.get_test_params()[i].
-        It should be a valid call for self.score.
+        Returns a list, the i-th element should be valid arguments for
+        self.evaluate and self.score, of an instance constructed with
+        self.get_test_params()[i].
 
         Returns
         -------
diff --git a/src/hyperactive/experiment/toy/_sphere.py b/src/hyperactive/experiment/toy/_sphere.py
index 7d405278..09e9e5c6 100644
--- a/src/hyperactive/experiment/toy/_sphere.py
+++ b/src/hyperactive/experiment/toy/_sphere.py
@@ -121,10 +121,11 @@ def get_test_params(cls, parameter_set="default"):
 
     @classmethod
     def _get_score_params(self):
-        """Return settings for testing the score function. Used in tests only.
+        """Return settings for testing score/evaluate functions. Used in tests only.
 
-        Returns a list, the i-th element corresponds to self.get_test_params()[i].
-        It should be a valid call for self.score.
+        Returns a list, the i-th element should be valid arguments for
+        self.evaluate and self.score, of an instance constructed with
+        self.get_test_params()[i].
 
         Returns
         -------

From a9f8a8f0d94c13795a818098e0558e4798d40914 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 19:39:48 +0200
Subject: [PATCH 22/23] Update _negative.py

---
 src/hyperactive/experiment/compose/_negative.py | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/hyperactive/experiment/compose/_negative.py b/src/hyperactive/experiment/compose/_negative.py
index 2614a0de..98e881e4 100644
--- a/src/hyperactive/experiment/compose/_negative.py
+++ b/src/hyperactive/experiment/compose/_negative.py
@@ -130,3 +130,19 @@ def get_test_params(cls, parameter_set="default"):
         params2 = {"experiment": ackley_exp, "flip_score": False}
 
         return [params0, params1, params2]
+
+    @classmethod
+    def _get_score_params(self):
+        """Return settings for testing score/evaluate functions. Used in tests only.
+
+        Returns a list, the i-th element should be valid arguments for
+        self.evaluate and self.score, of an instance constructed with
+        self.get_test_params()[i].
+
+        Returns
+        -------
+        list of dict
+            The parameters to be used for scoring.
+        """
+        params = {"x0": 0, "x1": 0}
+        return [params, params, params]

From d78f748264b83cba9ea17fe99a7258567fa659f7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20Kir=C3=A1ly?= <fkiraly@gcos.ai>
Date: Sun, 27 Jul 2025 19:54:44 +0200
Subject: [PATCH 23/23] Update _negative.py

---
 src/hyperactive/experiment/compose/_negative.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hyperactive/experiment/compose/_negative.py b/src/hyperactive/experiment/compose/_negative.py
index 98e881e4..bfb6d557 100644
--- a/src/hyperactive/experiment/compose/_negative.py
+++ b/src/hyperactive/experiment/compose/_negative.py
@@ -37,7 +37,7 @@ class Negative(BaseExperiment):
     Example
     -------
     >>> import numpy as np
-    >>> from hyperactive.toy.ackley import Ackley
+    >>> from hyperactive.experiment.toy import Ackley
     >>> from hyperactive.experiment.compose import Negative
     >>>
     >>> ackley_exp = Ackley(a=20, b=0.2, c=2 * np.pi, d=2)