diff --git a/examples/double_chain_q_learning/double_chain.py b/examples/double_chain_q_learning/double_chain.py
index 73386701..ec7ddcc5 100644
--- a/examples/double_chain_q_learning/double_chain.py
+++ b/examples/double_chain_q_learning/double_chain.py
@@ -51,7 +51,7 @@ def experiment(algorithm_class, exp):
 
 
 if __name__ == '__main__':
-    n_experiment = 500
+    n_experiment = 5
 
     names = {1: '1', .51: '51', QLearning: 'Q', DoubleQLearning: 'DQ',
              WeightedQLearning: 'WQ', SpeedyQLearning: 'SPQ'}
@@ -63,7 +63,7 @@ def experiment(algorithm_class, exp):
     for e in [1, .51]:
         for a in [QLearning, DoubleQLearning, WeightedQLearning,
                   SpeedyQLearning]:
-            out = Parallel(n_jobs=-1)(
+            out = Parallel(n_jobs=1)(
                 delayed(experiment)(a, e) for _ in range(n_experiment))
             Qs = np.array([o for o in out])
 
diff --git a/examples/habitat/habitat_nav_dqn.py b/examples/habitat/habitat_nav_dqn.py
index fa7396d5..5ab96822 100644
--- a/examples/habitat/habitat_nav_dqn.py
+++ b/examples/habitat/habitat_nav_dqn.py
@@ -13,7 +13,6 @@
 from mushroom_rl.core import Core, Logger
 from mushroom_rl.environments.habitat_env import *
 from mushroom_rl.policy import EpsGreedy
-from mushroom_rl.utils.dataset import compute_metrics
 from mushroom_rl.rl_utils.parameters import LinearParameter, Parameter
 from mushroom_rl.rl_utils.replay_memory import PrioritizedReplayMemory
 
@@ -132,7 +131,7 @@ def print_epoch(epoch, logger):
 
 
 def get_stats(dataset, logger):
-    score = compute_metrics(dataset)
+    score = dataset.compute_metrics()
     logger.info(('min_reward: %f, max_reward: %f, mean_reward: %f,'
                 ' median_reward: %f, episodes_completed: %d' % score))
 
diff --git a/examples/habitat/habitat_rearrange_sac.py b/examples/habitat/habitat_rearrange_sac.py
index e7afada2..8c1e699d 100644
--- a/examples/habitat/habitat_rearrange_sac.py
+++ b/examples/habitat/habitat_rearrange_sac.py
@@ -8,7 +8,6 @@
 from mushroom_rl.algorithms.actor_critic import SAC
 from mushroom_rl.core import Core, Logger
 from mushroom_rl.environments.habitat_env import *
-from mushroom_rl.utils.dataset import compute_J, parse_dataset
 
 from tqdm import trange
 
@@ -148,11 +147,10 @@ def experiment(alg, n_epochs, n_steps, n_episodes_test):
 
     # RUN
     dataset = core.evaluate(n_episodes=n_episodes_test, render=False)
-    s, *_ = parse_dataset(dataset)
 
-    J = np.mean(compute_J(dataset, mdp.info.gamma))
-    R = np.mean(compute_J(dataset))
-    E = agent.policy.entropy(s)
+    J = np.mean(dataset.discounted_return)
+    R = np.mean(dataset.undiscounted_return)
+    E = agent.policy.entropy(dataset.state)
 
     logger.epoch_info(0, J=J, R=R, entropy=E)
 
@@ -161,11 +159,10 @@ def experiment(alg, n_epochs, n_steps, n_episodes_test):
     for n in trange(n_epochs, leave=False):
         core.learn(n_steps=n_steps, n_steps_per_fit=1)
         dataset = core.evaluate(n_episodes=n_episodes_test, render=False)
-        s, *_ = parse_dataset(dataset)
 
-        J = np.mean(compute_J(dataset, mdp.info.gamma))
-        R = np.mean(compute_J(dataset))
-        E = agent.policy.entropy(s)
+        J = np.mean(dataset.discounted_return)
+        R = np.mean(dataset.undiscounted_return)
+        E = agent.policy.entropy(dataset.state)
 
         logger.epoch_info(n+1, J=J, R=R, entropy=E)