diff --git a/src/bayesvalidrox/surrogate_models/engine.py b/src/bayesvalidrox/surrogate_models/engine.py
index 0c4f15263973aa2329e601960740015e1c6f630e..a6d2447c6cae42413261361d2560feb678b928f7 100644
--- a/src/bayesvalidrox/surrogate_models/engine.py
+++ b/src/bayesvalidrox/surrogate_models/engine.py
@@ -439,7 +439,7 @@ class Engine:
                     if itr_no > 1:
                         pc_model = prev_meta_model_dict[itr_no - 1]
                         self.SeqDes._y_hat_prev, _ = pc_model.eval_metamodel(
-                            samples=x_full[-1].reshape(1, -1))
+                            x_full[-1].reshape(1, -1))
                         del prev_meta_model_dict[itr_no - 1]
                     if itr_no == 1 and self.ExpDesign.tradeoff_scheme == 'adaptive':
                         # TODO: this was added just as a fix, needs to be reworked
@@ -448,7 +448,7 @@ class Engine:
                         # print(x_prev.shape)
                         pc_model = prev_meta_model_dict[itr_no]
                         self.SeqDes._y_hat_prev, _ = pc_model.eval_metamodel(
-                            samples=x_prev)
+                            x_prev)
 
                     # Optimal Bayesian Design
                     # self.MetaModel.ExpDesignFlag = 'sequential'
@@ -474,7 +474,7 @@ class Engine:
                     if self.ExpDesign.adapt_verbose:
                         from .adaptPlot import adaptPlot
                         y_hat, std_hat = self.MetaModel.eval_metamodel(
-                            samples=x_new
+                            x_new
                         )
                         adaptPlot(
                             self.MetaModel, y_new, y_hat, std_hat,
@@ -701,7 +701,7 @@ class Engine:
         output_names = self.out_names
 
         # TODO: Evaluate MetaModel on the experimental design and ValidSet
-        OutputRS, _ = metamod.eval_metamodel(samples=samples)
+        OutputRS, _ = metamod.eval_metamodel(samples)
 
         logLik_data = np.zeros(n_samples)
         logLik_model = np.zeros(n_samples)
@@ -861,7 +861,7 @@ class Engine:
             )
 
             # Monte Carlo simulation for the candidate design
-            Y_MC, std_MC = self.MetaModel.eval_metamodel(samples=X_MC)
+            Y_MC, std_MC = self.MetaModel.eval_metamodel(X_MC)
 
             # Likelihood computation (Comparison of data and
             # simulation results via PCE with candidate design)
@@ -1000,7 +1000,7 @@ class Engine:
 
         # Run the PCE model with the generated samples
         valid_PCE_runs, _ = self.MetaModel.eval_metamodel(
-            samples=self.ExpDesign.valid_samples)
+            self.ExpDesign.valid_samples)
 
         rms_error = {}
         valid_error = {}
diff --git a/src/bayesvalidrox/surrogate_models/sequential_design.py b/src/bayesvalidrox/surrogate_models/sequential_design.py
index 2fb70febc0c1fc88bc73f7d12022d7a41f7d5b5f..a8039dd6194ae8e1d0398ec3255feea4cb83b71a 100644
--- a/src/bayesvalidrox/surrogate_models/sequential_design.py
+++ b/src/bayesvalidrox/surrogate_models/sequential_design.py
@@ -548,7 +548,7 @@ class SequentialDesign:
                 # New adaptive trade-off according to Liu et al. (2017)
                 # Mean squared error for last design point
                 last_EDX = old_EDX[-1].reshape(1, -1)
-                lastPCEY, _ = self.MetaModel.eval_metamodel(samples=last_EDX)
+                lastPCEY, _ = self.MetaModel.eval_metamodel(last_EDX)
                 pce_y = np.array(list(lastPCEY.values()))[:, 0]
                 y = np.array(list(old_EDY.values()))[:, -1, :]
                 mseError = mean_squared_error(pce_y, y)
@@ -607,7 +607,7 @@ class SequentialDesign:
             NCandidate = candidates.shape[0]
             U_J_d = np.zeros(NCandidate)
             # Evaluate all candidates
-            y_can, std_can = self.MetaModel.eval_metamodel(samples=candidates)
+            y_can, std_can = self.MetaModel.eval_metamodel(candidates)
             # loop through candidates
             for idx, X_can in tqdm(enumerate(candidates), ascii=True,
                                    desc="BAL Design"):
@@ -659,7 +659,7 @@ class SequentialDesign:
 
         # Run the Metamodel for the candidate
         X_can = X_can.reshape(1, -1)
-        Y_PC_can, std_PC_can = MetaModel.eval_metamodel(samples=X_can)
+        Y_PC_can, std_PC_can = MetaModel.eval_metamodel(X_can)
 
         score = None
         if util_func.lower() == 'alm':
@@ -876,14 +876,14 @@ class SequentialDesign:
         # Compute the mean and std based on the MetaModel
         # pce_means, pce_stds = self._compute_pce_moments(MetaModel)
         if var.lower() == 'alc':
-            Y_MC, Y_MC_std = MetaModel.eval_metamodel(samples=X_MC)
+            Y_MC, Y_MC_std = MetaModel.eval_metamodel(X_MC)
 
         # Old Experimental design
         oldExpDesignX = self.ExpDesign.X
         oldExpDesignY = self.ExpDesign.Y
 
         # Evaluate the PCE metamodels at that location ???
-        Y_PC_can, Y_std_can = MetaModel.eval_metamodel(samples=X_can)
+        Y_PC_can, Y_std_can = MetaModel.eval_metamodel(X_can)
         PCE_Model_can = deepcopy(MetaModel)
         # TODO: this is really not clean, create a workaround for this issue!
         engine_can = deepcopy(self.engine)
@@ -916,7 +916,7 @@ class SequentialDesign:
         if var.lower() == 'mi':
             # Mutual information based on Krause et al.
             # Adapted from Beck & Guillas (MICE) paper
-            _, std_PC_can = engine_can.MetaModel.eval_metamodel(samples=X_can)
+            _, std_PC_can = engine_can.MetaModel.eval_metamodel(X_can)
             std_can = {key: std_PC_can[key] for key in out_names}
 
             std_old = {key: Y_std_can[key] for key in out_names}
@@ -934,8 +934,7 @@ class SequentialDesign:
             # metrics, 51 (2009), pp. 130–145.
 
             # Evaluate the MetaModel at the given samples
-            _, Y_MC_std_can = engine_can.MetaModel.eval_metamodel(
-                samples=X_MC)
+            _, Y_MC_std_can = engine_can.MetaModel.eval_metamodel(X_MC)
 
             # Compute the score
             score = []
@@ -962,7 +961,7 @@ class SequentialDesign:
                 )
 
             # Evaluate the MetaModel at the given samples
-            Y_MC, std_MC = PCE_Model_can.eval_metamodel(samples=X_MC)
+            Y_MC, std_MC = PCE_Model_can.eval_metamodel(X_MC)
 
             # Likelihood computation (Comparison of data and simulation
             # results via PCE with candidate design)
@@ -1299,7 +1298,7 @@ class SequentialDesign:
         output_names = self.out_names
 
         # TODO: Evaluate MetaModel on the experimental design and ValidSet
-        OutputRS, _ = MetaModel.eval_metamodel(samples=samples)
+        OutputRS, _ = MetaModel.eval_metamodel(samples)
 
         logLik_data = np.zeros(n_samples)
         logLik_model = np.zeros(n_samples)
@@ -1396,7 +1395,7 @@ class SequentialDesign:
             )
 
             # Monte Carlo simulation for the candidate design
-            Y_MC, std_MC = self.MetaModel.eval_metamodel(samples=X_MC)
+            Y_MC, std_MC = self.MetaModel.eval_metamodel(X_MC)
 
             # Likelihood computation (Comparison of data and
             # simulation results via PCE with candidate design)
@@ -1534,8 +1533,7 @@ class SequentialDesign:
         valid_model_runs = self.ExpDesign.valid_model_runs
 
         # Run the PCE model with the generated samples
-        valid_PCE_runs, _ = self.MetaModel.eval_metamodel(
-            samples=self.ExpDesign.valid_samples)
+        valid_PCE_runs, _ = self.MetaModel.eval_metamodel(self.ExpDesign.valid_samples)
 
         rms_error = {}
         valid_error = {}