diff --git a/examples/atari/atari_network.py b/examples/atari/atari_network.py
index 0767eb7..bd16d4f 100644
--- a/examples/atari/atari_network.py
+++ b/examples/atari/atari_network.py
@@ -8,9 +8,11 @@ from torch import nn
 from tianshou.highlevel.env import Environments
 from tianshou.highlevel.module.actor import ActorFactory
 from tianshou.highlevel.module.core import (
+    TDevice,
+)
+from tianshou.highlevel.module.intermediate import (
     IntermediateModule,
     IntermediateModuleFactory,
-    TDevice,
 )
 from tianshou.utils.net.discrete import Actor, NoisyLinear
 
diff --git a/tianshou/highlevel/agent.py b/tianshou/highlevel/agent.py
index 38407a8..7ac2ae7 100644
--- a/tianshou/highlevel/agent.py
+++ b/tianshou/highlevel/agent.py
@@ -81,6 +81,8 @@ log = logging.getLogger(__name__)
 
 
 class AgentFactory(ABC, ToStringMixin):
+    """Factory for the creation of an agent's policy, its trainer as well as collectors."""
+
     def __init__(self, sampling_config: SamplingConfig, optim_factory: OptimizerFactory):
         self.sampling_config = sampling_config
         self.optim_factory = optim_factory
diff --git a/tianshou/highlevel/env.py b/tianshou/highlevel/env.py
index f356f4d..6fdc970 100644
--- a/tianshou/highlevel/env.py
+++ b/tianshou/highlevel/env.py
@@ -14,6 +14,8 @@ TObservationShape: TypeAlias = int | Sequence[int]
 
 
 class EnvType(Enum):
+    """Enumeration of environment types."""
+
     CONTINUOUS = "continuous"
     DISCRETE = "discrete"
 
@@ -33,6 +35,8 @@ class EnvType(Enum):
 
 
 class Environments(ToStringMixin, ABC):
+    """Represents (vectorized) environments."""
+
     def __init__(self, env: gym.Env, train_envs: BaseVectorEnv, test_envs: BaseVectorEnv):
         self.env = env
         self.train_envs = train_envs
@@ -52,6 +56,11 @@ class Environments(ToStringMixin, ABC):
         }
 
     def set_persistence(self, *p: Persistence) -> None:
+        """Associates the given persistence handlers which may persist and restore
+        environment-specific information.
+
+        :param p: persistence handlers
+        """
         self.persistence = p
 
     @abstractmethod
@@ -74,6 +83,8 @@ class Environments(ToStringMixin, ABC):
 
 
 class ContinuousEnvironments(Environments):
+    """Represents (vectorized) continuous environments."""
+
     def __init__(self, env: gym.Env, train_envs: BaseVectorEnv, test_envs: BaseVectorEnv):
         super().__init__(env, train_envs, test_envs)
         self.state_shape, self.action_shape, self.max_action = self._get_continuous_env_info(env)
@@ -110,6 +121,8 @@ class ContinuousEnvironments(Environments):
 
 
 class DiscreteEnvironments(Environments):
+    """Represents (vectorized) discrete environments."""
+
     def __init__(self, env: gym.Env, train_envs: BaseVectorEnv, test_envs: BaseVectorEnv):
         super().__init__(env, train_envs, test_envs)
         self.observation_shape = env.observation_space.shape or env.observation_space.n  # type: ignore
diff --git a/tianshou/highlevel/experiment.py b/tianshou/highlevel/experiment.py
index ed2575d..f22ea6d 100644
--- a/tianshou/highlevel/experiment.py
+++ b/tianshou/highlevel/experiment.py
@@ -27,7 +27,7 @@ from tianshou.highlevel.agent import (
 )
 from tianshou.highlevel.config import SamplingConfig
 from tianshou.highlevel.env import EnvFactory, Environments
-from tianshou.highlevel.logger import DefaultLoggerFactory, LoggerFactory, TLogger
+from tianshou.highlevel.logger import LoggerFactory, LoggerFactoryDefault, TLogger
 from tianshou.highlevel.module.actor import (
     ActorFactory,
     ActorFactoryDefault,
@@ -38,8 +38,6 @@ from tianshou.highlevel.module.actor import (
     IntermediateModuleFactoryFromActorFactory,
 )
 from tianshou.highlevel.module.core import (
-    ImplicitQuantileNetworkFactory,
-    IntermediateModuleFactory,
     TDevice,
 )
 from tianshou.highlevel.module.critic import (
@@ -49,6 +47,8 @@ from tianshou.highlevel.module.critic import (
     CriticFactoryDefault,
     CriticFactoryReuseActor,
 )
+from tianshou.highlevel.module.intermediate import IntermediateModuleFactory
+from tianshou.highlevel.module.special import ImplicitQuantileNetworkFactory
 from tianshou.highlevel.optim import OptimizerFactory, OptimizerFactoryAdam
 from tianshou.highlevel.params.policy_params import (
     A2CParams,
@@ -116,8 +116,12 @@ class ExperimentConfig:
 
 @dataclass
 class ExperimentResult:
+    """Contains the results of an experiment."""
+
     world: World
+    """contains all the essential instances of the experiment"""
     trainer_result: dict[str, Any] | None
+    """dictionary of results as returned by the trained (if any)"""
 
 
 class Experiment(Generic[TPolicy, TTrainer], ToStringMixin):
@@ -140,7 +144,7 @@ class Experiment(Generic[TPolicy, TTrainer], ToStringMixin):
         env_config: PersistableConfigProtocol | None = None,
     ):
         if logger_factory is None:
-            logger_factory = DefaultLoggerFactory()
+            logger_factory = LoggerFactoryDefault()
         self.config = config
         self.env_factory = env_factory
         self.agent_factory = agent_factory
@@ -179,7 +183,9 @@ class Experiment(Generic[TPolicy, TTrainer], ToStringMixin):
             pickle.dump(self, f)
 
     def run(
-        self, experiment_name: str | None = None, logger_run_id: str | None = None,
+        self,
+        experiment_name: str | None = None,
+        logger_run_id: str | None = None,
     ) -> ExperimentResult:
         """:param experiment_name: the experiment name, which corresponds to the directory (within the logging
             directory) where all results associated with the experiment will be saved.
@@ -317,14 +323,31 @@ class ExperimentBuilder:
         return self
 
     def with_logger_factory(self, logger_factory: LoggerFactory) -> Self:
+        """Allows to customize the logger factory to use.
+        If this method is not called, the default logger factory :class:`LoggerFactoryDefault` will be used.
+
+        :param logger_factory: the factory to use
+        :return: the builder
+        """
         self._logger_factory = logger_factory
         return self
 
     def with_policy_wrapper_factory(self, policy_wrapper_factory: PolicyWrapperFactory) -> Self:
+        """Allows to define a wrapper around the policy that is created, extending the original policy.
+
+        :param policy_wrapper_factory: the factory for the wrapper
+        :return: the builder
+        """
         self._policy_wrapper_factory = policy_wrapper_factory
         return self
 
     def with_optim_factory(self, optim_factory: OptimizerFactory) -> Self:
+        """Allows to customize the gradient-based optimizer to use.
+        By default, :class:`OptimizerFactoryAdam` will be used with default parameters.
+
+        :param optim_factory: the optimizer factory
+        :return: the builder
+        """
         self._optim_factory = optim_factory
         return self
 
@@ -345,14 +368,30 @@ class ExperimentBuilder:
         return self
 
     def with_trainer_epoch_callback_train(self, callback: TrainerEpochCallbackTrain) -> Self:
+        """Allows to define a callback function which is called at the beginning of every epoch during training.
+
+        :param callback: the callback
+        :return: the builder
+        """
         self._trainer_callbacks.epoch_callback_train = callback
         return self
 
     def with_trainer_epoch_callback_test(self, callback: TrainerEpochCallbackTest) -> Self:
+        """Allows to define a callback function which is called at the beginning of testing in each epoch.
+
+        :param callback: the callback
+        :return: the builder
+        """
         self._trainer_callbacks.epoch_callback_test = callback
         return self
 
     def with_trainer_stop_callback(self, callback: TrainerStopCallback) -> Self:
+        """Allows to define a callback that decides whether training shall stop early.
+        The callback receives the undiscounted returns of the testing result.
+
+        :param callback: the callback
+        :return: the builder
+        """
         self._trainer_callbacks.stop_callback = callback
         return self
 
@@ -367,6 +406,10 @@ class ExperimentBuilder:
             return self._optim_factory
 
     def build(self) -> Experiment:
+        """Creates the experiment based on the options specified via this builder.
+
+        :return: the experiment
+        """
         agent_factory = self._create_agent_factory()
         agent_factory.set_trainer_callbacks(self._trainer_callbacks)
         if self._policy_wrapper_factory:
@@ -388,6 +431,12 @@ class _BuilderMixinActorFactory(ActorFutureProviderProtocol):
         self._actor_factory: ActorFactory | None = None
 
     def with_actor_factory(self, actor_factory: ActorFactory) -> Self:
+        """Allows to customize the actor component via the specification of a factory.
+        If this function is not called, a default actor factory (with default parameters) will be used.
+
+        :param actor_factory: the factory to use for the creation of the actor network
+        :return: the builder
+        """
         self._actor_factory = actor_factory
         return self
 
@@ -397,6 +446,12 @@ class _BuilderMixinActorFactory(ActorFutureProviderProtocol):
         continuous_unbounded: bool = False,
         continuous_conditioned_sigma: bool = False,
     ) -> Self:
+        """:param hidden_sizes: the sequence of hidden dimensions to use in the network structure
+        :param continuous_unbounded: whether, for continuous action spaces, to apply tanh activation on final logits
+        :param continuous_conditioned_sigma: whether, for continuous action spaces, the standard deviation of continuous actions (sigma)
+            shall be computed from the input; if False, sigma is an independent parameter.
+        :return: the builder
+        """
         self._actor_factory = ActorFactoryDefault(
             self._continuous_actor_type,
             hidden_sizes,
@@ -406,6 +461,7 @@ class _BuilderMixinActorFactory(ActorFutureProviderProtocol):
         return self
 
     def get_actor_future(self) -> ActorFuture:
+        """:return: an object, which, in the future, will contain the actor instance that is created for the experiment."""
         return self._actor_future
 
     def _get_actor_factory(self) -> ActorFactory:
@@ -431,6 +487,15 @@ class _BuilderMixinActorFactory_ContinuousGaussian(_BuilderMixinActorFactory):
         continuous_unbounded: bool = False,
         continuous_conditioned_sigma: bool = False,
     ) -> Self:
+        """Defines use of the default actor factory, allowing its parameters it to be customized.
+        The default actor factory uses an MLP-style architecture.
+
+        :param hidden_sizes: dimensions of hidden layers used by the network
+        :param continuous_unbounded: whether, for continuous action spaces, to apply tanh activation on final logits
+        :param continuous_conditioned_sigma: whether, for continuous action spaces, the standard deviation of continuous actions (sigma)
+            shall be computed from the input; if False, sigma is an independent parameter.
+        :return: the builder
+        """
         return super()._with_actor_factory_default(
             hidden_sizes,
             continuous_unbounded=continuous_unbounded,
@@ -445,6 +510,12 @@ class _BuilderMixinActorFactory_ContinuousDeterministic(_BuilderMixinActorFactor
         super().__init__(ContinuousActorType.DETERMINISTIC)
 
     def with_actor_factory_default(self, hidden_sizes: Sequence[int]) -> Self:
+        """Defines use of the default actor factory, allowing its parameters it to be customized.
+        The default actor factory uses an MLP-style architecture.
+
+        :param hidden_sizes: dimensions of hidden layers used by the network
+        :return: the builder
+        """
         return super()._with_actor_factory_default(hidden_sizes)
 
 
@@ -480,6 +551,11 @@ class _BuilderMixinSingleCriticFactory(_BuilderMixinCriticsFactory):
         super().__init__(1, actor_future_provider)
 
     def with_critic_factory(self, critic_factory: CriticFactory) -> Self:
+        """Specifies that the given factory shall be used for the critic.
+
+        :param critic_factory: the critic factory
+        :return: the builder
+        """
         self._with_critic_factory(0, critic_factory)
         return self
 
@@ -487,6 +563,11 @@ class _BuilderMixinSingleCriticFactory(_BuilderMixinCriticsFactory):
         self,
         hidden_sizes: Sequence[int] = CriticFactoryDefault.DEFAULT_HIDDEN_SIZES,
     ) -> Self:
+        """Makes the critic use the default, MLP-style architecture with the given parameters.
+
+        :param hidden_sizes: the sequence of dimensions to use in hidden layers of the network
+        :return: the builder
+        """
         self._with_critic_factory_default(0, hidden_sizes)
         return self
 
@@ -496,7 +577,7 @@ class _BuilderMixinSingleCriticCanUseActorFactory(_BuilderMixinSingleCriticFacto
         super().__init__(actor_future_provider)
 
     def with_critic_factory_use_actor(self) -> Self:
-        """Makes the critic use the same network as the actor."""
+        """Makes the first critic reuse the actor's preprocessing network (parameter sharing)."""
         return self._with_critic_factory_use_actor(0)
 
 
@@ -505,6 +586,11 @@ class _BuilderMixinDualCriticFactory(_BuilderMixinCriticsFactory):
         super().__init__(2, actor_future_provider)
 
     def with_common_critic_factory(self, critic_factory: CriticFactory) -> Self:
+        """Specifies that the given factory shall be used for both critics.
+
+        :param critic_factory: the critic factory
+        :return: the builder
+        """
         for i in range(len(self._critic_factories)):
             self._with_critic_factory(i, critic_factory)
         return self
@@ -513,17 +599,27 @@ class _BuilderMixinDualCriticFactory(_BuilderMixinCriticsFactory):
         self,
         hidden_sizes: Sequence[int] = CriticFactoryDefault.DEFAULT_HIDDEN_SIZES,
     ) -> Self:
+        """Makes both critics use the default, MLP-style architecture with the given parameters.
+
+        :param hidden_sizes: the sequence of dimensions to use in hidden layers of the network
+        :return: the builder
+        """
         for i in range(len(self._critic_factories)):
             self._with_critic_factory_default(i, hidden_sizes)
         return self
 
     def with_common_critic_factory_use_actor(self) -> Self:
-        """Makes all critics use the same network as the actor."""
+        """Makes both critics reuse the actor's preprocessing network (parameter sharing)."""
         for i in range(len(self._critic_factories)):
             self._with_critic_factory_use_actor(i)
         return self
 
     def with_critic1_factory(self, critic_factory: CriticFactory) -> Self:
+        """Specifies that the given factory shall be used for the first critic.
+
+        :param critic_factory: the critic factory
+        :return: the builder
+        """
         self._with_critic_factory(0, critic_factory)
         return self
 
@@ -531,14 +627,24 @@ class _BuilderMixinDualCriticFactory(_BuilderMixinCriticsFactory):
         self,
         hidden_sizes: Sequence[int] = CriticFactoryDefault.DEFAULT_HIDDEN_SIZES,
     ) -> Self:
+        """Makes the first critic use the default, MLP-style architecture with the given parameters.
+
+        :param hidden_sizes: the sequence of dimensions to use in hidden layers of the network
+        :return: the builder
+        """
         self._with_critic_factory_default(0, hidden_sizes)
         return self
 
     def with_critic1_factory_use_actor(self) -> Self:
-        """Makes the critic use the same network as the actor."""
+        """Makes the first critic reuse the actor's preprocessing network (parameter sharing)."""
         return self._with_critic_factory_use_actor(0)
 
     def with_critic2_factory(self, critic_factory: CriticFactory) -> Self:
+        """Specifies that the given factory shall be used for the second critic.
+
+        :param critic_factory: the critic factory
+        :return: the builder
+        """
         self._with_critic_factory(1, critic_factory)
         return self
 
@@ -546,11 +652,16 @@ class _BuilderMixinDualCriticFactory(_BuilderMixinCriticsFactory):
         self,
         hidden_sizes: Sequence[int] = CriticFactoryDefault.DEFAULT_HIDDEN_SIZES,
     ) -> Self:
+        """Makes the second critic use the default, MLP-style architecture with the given parameters.
+
+        :param hidden_sizes: the sequence of dimensions to use in hidden layers of the network
+        :return: the builder
+        """
         self._with_critic_factory_default(0, hidden_sizes)
         return self
 
     def with_critic2_factory_use_actor(self) -> Self:
-        """Makes the second critic use the same network as the actor."""
+        """Makes the first critic reuse the actor's preprocessing network (parameter sharing)."""
         return self._with_critic_factory_use_actor(1)
 
 
@@ -559,6 +670,12 @@ class _BuilderMixinCriticEnsembleFactory:
         self.critic_ensemble_factory: CriticEnsembleFactory | None = None
 
     def with_critic_ensemble_factory(self, factory: CriticEnsembleFactory) -> Self:
+        """Specifies that the given factory shall be used for the critic ensemble.
+        If unspecified, the default factory (:class:`CriticEnsembleFactoryDefault`) is used.
+
+        :param critic_factory: the critic factory
+        :return: the builder
+        """
         self.critic_ensemble_factory = factory
         return self
 
@@ -566,6 +683,11 @@ class _BuilderMixinCriticEnsembleFactory:
         self,
         hidden_sizes: Sequence[int] = CriticFactoryDefault.DEFAULT_HIDDEN_SIZES,
     ) -> Self:
+        """Allows to customize the parameters of the default critic ensemble factory.
+
+        :param hidden_sizes: the sequence of sizes of hidden layers in the network architecture
+        :return: the builder
+        """
         self.critic_ensemble_factory = CriticEnsembleFactoryDefault(hidden_sizes)
         return self
 
diff --git a/tianshou/highlevel/logger.py b/tianshou/highlevel/logger.py
index c10599a..3458b6e 100644
--- a/tianshou/highlevel/logger.py
+++ b/tianshou/highlevel/logger.py
@@ -27,7 +27,7 @@ class LoggerFactory(ToStringMixin, ABC):
         """
 
 
-class DefaultLoggerFactory(LoggerFactory):
+class LoggerFactoryDefault(LoggerFactory):
     def __init__(
         self,
         logger_type: Literal["tensorboard", "wandb"] = "tensorboard",
diff --git a/tianshou/highlevel/module/actor.py b/tianshou/highlevel/module/actor.py
index d3f31f6..b1d4792 100644
--- a/tianshou/highlevel/module/actor.py
+++ b/tianshou/highlevel/module/actor.py
@@ -9,12 +9,14 @@ from torch import nn
 
 from tianshou.highlevel.env import Environments, EnvType
 from tianshou.highlevel.module.core import (
-    IntermediateModule,
-    IntermediateModuleFactory,
     ModuleFactory,
     TDevice,
     init_linear_orthogonal,
 )
+from tianshou.highlevel.module.intermediate import (
+    IntermediateModule,
+    IntermediateModuleFactory,
+)
 from tianshou.highlevel.module.module_opt import ModuleOpt
 from tianshou.highlevel.optim import OptimizerFactory
 from tianshou.utils.net import continuous, discrete
@@ -157,6 +159,11 @@ class ActorFactoryContinuousGaussianNet(ActorFactoryContinuous):
         unbounded: bool = True,
         conditioned_sigma: bool = False,
     ):
+        """:param hidden_sizes: the sequence of hidden dimensions to use in the network structure
+        :param unbounded: whether to apply tanh activation on final logits
+        :param conditioned_sigma: if True, the standard deviation of continuous actions (sigma) is computed from the
+            input; if False, sigma is an independent parameter
+        """
         self.hidden_sizes = hidden_sizes
         self.unbounded = unbounded
         self.conditioned_sigma = conditioned_sigma
diff --git a/tianshou/highlevel/module/core.py b/tianshou/highlevel/module/core.py
index 08fc88e..61f4a23 100644
--- a/tianshou/highlevel/module/core.py
+++ b/tianshou/highlevel/module/core.py
@@ -1,14 +1,10 @@
 from abc import ABC, abstractmethod
-from collections.abc import Sequence
-from dataclasses import dataclass
 from typing import TypeAlias
 
 import numpy as np
 import torch
 
 from tianshou.highlevel.env import Environments
-from tianshou.utils.net.discrete import ImplicitQuantileNetwork
-from tianshou.utils.string import ToStringMixin
 
 TDevice: TypeAlias = str | torch.device
 
@@ -25,44 +21,8 @@ def init_linear_orthogonal(module: torch.nn.Module) -> None:
 
 
 class ModuleFactory(ABC):
+    """Represents a factory for the creation of a torch module given an environment and target device."""
+
     @abstractmethod
     def create_module(self, envs: Environments, device: TDevice) -> torch.nn.Module:
         pass
-
-
-@dataclass
-class IntermediateModule:
-    module: torch.nn.Module
-    output_dim: int
-
-
-class IntermediateModuleFactory(ToStringMixin, ModuleFactory, ABC):
-    @abstractmethod
-    def create_intermediate_module(self, envs: Environments, device: TDevice) -> IntermediateModule:
-        pass
-
-    def create_module(self, envs: Environments, device: TDevice) -> torch.nn.Module:
-        return self.create_intermediate_module(envs, device).module
-
-
-class ImplicitQuantileNetworkFactory(ModuleFactory, ToStringMixin):
-    def __init__(
-        self,
-        preprocess_net_factory: IntermediateModuleFactory,
-        hidden_sizes: Sequence[int] = (),
-        num_cosines: int = 64,
-    ):
-        self.preprocess_net_factory = preprocess_net_factory
-        self.hidden_sizes = hidden_sizes
-        self.num_cosines = num_cosines
-
-    def create_module(self, envs: Environments, device: TDevice) -> ImplicitQuantileNetwork:
-        preprocess_net = self.preprocess_net_factory.create_intermediate_module(envs, device)
-        return ImplicitQuantileNetwork(
-            preprocess_net=preprocess_net.module,
-            action_shape=envs.get_action_shape(),
-            hidden_sizes=self.hidden_sizes,
-            num_cosines=self.num_cosines,
-            preprocess_net_output_dim=preprocess_net.output_dim,
-            device=device,
-        ).to(device)
diff --git a/tianshou/highlevel/module/critic.py b/tianshou/highlevel/module/critic.py
index 54b6003..1576bc2 100644
--- a/tianshou/highlevel/module/critic.py
+++ b/tianshou/highlevel/module/critic.py
@@ -15,6 +15,8 @@ from tianshou.utils.string import ToStringMixin
 
 
 class CriticFactory(ToStringMixin, ABC):
+    """Represents a factory for the generation of a critic module."""
+
     @abstractmethod
     def create_module(
         self,
@@ -23,9 +25,11 @@ class CriticFactory(ToStringMixin, ABC):
         use_action: bool,
         discrete_last_size_use_action_shape: bool = False,
     ) -> nn.Module:
-        """:param envs: the environments
+        """Creates the critic module.
+
+        :param envs: the environments
         :param device: the torch device
-        :param use_action: whether to (additionally) expect the action as input
+        :param use_action: whether to expect the action as an additional input (in addition to the observations)
         :param discrete_last_size_use_action_shape: whether, for the discrete case, the output dimension shall use the action shape
         :return: the module
         """
@@ -39,6 +43,16 @@ class CriticFactory(ToStringMixin, ABC):
         lr: float,
         discrete_last_size_use_action_shape: bool = False,
     ) -> ModuleOpt:
+        """Creates the critic module along with its optimizer for the given learning rate.
+
+        :param envs: the environments
+        :param device: the torch device
+        :param use_action: whether to expect the action as an additional input (in addition to the observations)
+        :param optim_factory: the optimizer factory
+        :param lr: the learning rate
+        :param discrete_last_size_use_action_shape: whether, for the discrete case, the output dimension shall use the action shape
+        :return:
+        """
         module = self.create_module(
             envs,
             device,
diff --git a/tianshou/highlevel/module/intermediate.py b/tianshou/highlevel/module/intermediate.py
new file mode 100644
index 0000000..a008935
--- /dev/null
+++ b/tianshou/highlevel/module/intermediate.py
@@ -0,0 +1,27 @@
+from abc import ABC, abstractmethod
+from dataclasses import dataclass
+
+import torch
+
+from tianshou.highlevel.env import Environments
+from tianshou.highlevel.module.core import ModuleFactory, TDevice
+from tianshou.utils.string import ToStringMixin
+
+
+@dataclass
+class IntermediateModule:
+    """Container for a module which computes an intermediate representation (with a known dimension)."""
+
+    module: torch.nn.Module
+    output_dim: int
+
+
+class IntermediateModuleFactory(ToStringMixin, ModuleFactory, ABC):
+    """Factory for the generation of a module which computes an intermediate representation."""
+
+    @abstractmethod
+    def create_intermediate_module(self, envs: Environments, device: TDevice) -> IntermediateModule:
+        pass
+
+    def create_module(self, envs: Environments, device: TDevice) -> torch.nn.Module:
+        return self.create_intermediate_module(envs, device).module
diff --git a/tianshou/highlevel/module/module_opt.py b/tianshou/highlevel/module/module_opt.py
index 43242d8..222d680 100644
--- a/tianshou/highlevel/module/module_opt.py
+++ b/tianshou/highlevel/module/module_opt.py
@@ -7,12 +7,16 @@ from tianshou.utils.net.common import ActorCritic
 
 @dataclass
 class ModuleOpt:
+    """Container for a torch module along with its optimizer."""
+
     module: torch.nn.Module
     optim: torch.optim.Optimizer
 
 
 @dataclass
 class ActorCriticModuleOpt:
+    """Container for an :class:`ActorCritic` instance along with its optimizer."""
+
     actor_critic_module: ActorCritic
     optim: torch.optim.Optimizer
 
diff --git a/tianshou/highlevel/module/special.py b/tianshou/highlevel/module/special.py
new file mode 100644
index 0000000..8c3c568
--- /dev/null
+++ b/tianshou/highlevel/module/special.py
@@ -0,0 +1,30 @@
+from collections.abc import Sequence
+
+from tianshou.highlevel.env import Environments
+from tianshou.highlevel.module.core import ModuleFactory, TDevice
+from tianshou.highlevel.module.intermediate import IntermediateModuleFactory
+from tianshou.utils.net.discrete import ImplicitQuantileNetwork
+from tianshou.utils.string import ToStringMixin
+
+
+class ImplicitQuantileNetworkFactory(ModuleFactory, ToStringMixin):
+    def __init__(
+        self,
+        preprocess_net_factory: IntermediateModuleFactory,
+        hidden_sizes: Sequence[int] = (),
+        num_cosines: int = 64,
+    ):
+        self.preprocess_net_factory = preprocess_net_factory
+        self.hidden_sizes = hidden_sizes
+        self.num_cosines = num_cosines
+
+    def create_module(self, envs: Environments, device: TDevice) -> ImplicitQuantileNetwork:
+        preprocess_net = self.preprocess_net_factory.create_intermediate_module(envs, device)
+        return ImplicitQuantileNetwork(
+            preprocess_net=preprocess_net.module,
+            action_shape=envs.get_action_shape(),
+            hidden_sizes=self.hidden_sizes,
+            num_cosines=self.num_cosines,
+            preprocess_net_output_dim=preprocess_net.output_dim,
+            device=device,
+        ).to(device)
diff --git a/tianshou/highlevel/optim.py b/tianshou/highlevel/optim.py
index 008321f..8697e05 100644
--- a/tianshou/highlevel/optim.py
+++ b/tianshou/highlevel/optim.py
@@ -13,10 +13,6 @@ class OptimizerWithLearningRateProtocol(Protocol):
 
 
 class OptimizerFactory(ABC, ToStringMixin):
-    # TODO: Is it OK to assume that all optimizers have a learning rate argument?
-    # Right now, the learning rate is typically a configuration parameter.
-    # If we drop the assumption, we can't have that and will need to move the parameter
-    # to the optimizer factory, which is inconvenient for the user.
     @abstractmethod
     def create_optimizer(self, module: torch.nn.Module, lr: float) -> torch.optim.Optimizer:
         pass
diff --git a/tianshou/highlevel/params/lr_scheduler.py b/tianshou/highlevel/params/lr_scheduler.py
index 820be2e..93b1ce0 100644
--- a/tianshou/highlevel/params/lr_scheduler.py
+++ b/tianshou/highlevel/params/lr_scheduler.py
@@ -9,6 +9,8 @@ from tianshou.utils.string import ToStringMixin
 
 
 class LRSchedulerFactory(ToStringMixin, ABC):
+    """Factory for the createion of a learning rate scheduler."""
+
     @abstractmethod
     def create_scheduler(self, optim: torch.optim.Optimizer) -> LRScheduler:
         pass
diff --git a/tianshou/highlevel/params/noise.py b/tianshou/highlevel/params/noise.py
index 106e002..d3e4ce6 100644
--- a/tianshou/highlevel/params/noise.py
+++ b/tianshou/highlevel/params/noise.py
@@ -18,9 +18,12 @@ class NoiseFactoryMaxActionScaledGaussian(NoiseFactory):
     """
 
     def __init__(self, std_fraction: float):
+        """:param std_fraction: fraction (between 0 and 1) of the maximum action value that shall
+        be used as the standard deviation
+        """
         self.std_fraction = std_fraction
 
-    def create_noise(self, envs: Environments) -> BaseNoise:
+    def create_noise(self, envs: Environments) -> GaussianNoise:
         envs.get_type().assert_continuous(self)
         envs: ContinuousEnvironments
         return GaussianNoise(sigma=envs.max_action * self.std_fraction)
diff --git a/tianshou/highlevel/params/policy_params.py b/tianshou/highlevel/params/policy_params.py
index 33c9783..9d8cd53 100644
--- a/tianshou/highlevel/params/policy_params.py
+++ b/tianshou/highlevel/params/policy_params.py
@@ -241,7 +241,9 @@ class Params(GetParamTransformersProtocol):
 @dataclass
 class ParamsMixinLearningRateWithScheduler(GetParamTransformersProtocol):
     lr: float = 1e-3
+    """the learning rate to use in the gradient-based optimizer"""
     lr_scheduler_factory: LRSchedulerFactory | None = None
+    """factory for the creation of a learning rate scheduler"""
 
     def _get_param_transformers(self) -> list[ParamTransformer]:
         return [
diff --git a/tianshou/highlevel/params/policy_wrapper.py b/tianshou/highlevel/params/policy_wrapper.py
index 44d0f82..c821f50 100644
--- a/tianshou/highlevel/params/policy_wrapper.py
+++ b/tianshou/highlevel/params/policy_wrapper.py
@@ -3,7 +3,8 @@ from collections.abc import Sequence
 from typing import Generic, TypeVar
 
 from tianshou.highlevel.env import Environments
-from tianshou.highlevel.module.core import IntermediateModuleFactory, TDevice
+from tianshou.highlevel.module.core import TDevice
+from tianshou.highlevel.module.intermediate import IntermediateModuleFactory
 from tianshou.highlevel.optim import OptimizerFactory
 from tianshou.policy import BasePolicy, ICMPolicy
 from tianshou.utils.net.discrete import IntrinsicCuriosityModule
diff --git a/tianshou/highlevel/persistence.py b/tianshou/highlevel/persistence.py
index fad4bea..54f3c23 100644
--- a/tianshou/highlevel/persistence.py
+++ b/tianshou/highlevel/persistence.py
@@ -50,6 +50,8 @@ class Persistence(ABC):
 
 
 class PersistenceGroup(Persistence):
+    """Groups persistence handler such that they can be applied collectively."""
+
     def __init__(self, *p: Persistence, enabled: bool = True):
         self.items = p
         self.enabled = enabled
@@ -69,7 +71,7 @@ class PolicyPersistence:
     FILENAME = "policy.dat"
 
     def __init__(self, additional_persistence: Persistence | None = None, enabled: bool = True):
-        """:param additional_persistence: a persistence instance which is to be envoked whenever
+        """:param additional_persistence: a persistence instance which is to be invoked whenever
             this object is used to persist/restore data
         :param enabled: whether persistence is enabled (restoration is always enabled)
         """
diff --git a/tianshou/highlevel/trainer.py b/tianshou/highlevel/trainer.py
index 770c92b..2388e2a 100644
--- a/tianshou/highlevel/trainer.py
+++ b/tianshou/highlevel/trainer.py
@@ -52,6 +52,7 @@ class TrainerStopCallback(ToStringMixin, ABC):
     @abstractmethod
     def should_stop(self, mean_rewards: float, context: TrainingContext) -> bool:
         """:param mean_rewards: the average undiscounted returns of the testing result
+        :param context: the training context
         :return: True if the goal has been reached and training should stop, False otherwise
         """
 
@@ -64,6 +65,8 @@ class TrainerStopCallback(ToStringMixin, ABC):
 
 @dataclass
 class TrainerCallbacks:
+    """Container for callbacks used during training."""
+
     epoch_callback_train: TrainerEpochCallbackTrain | None = None
     epoch_callback_test: TrainerEpochCallbackTest | None = None
     stop_callback: TrainerStopCallback | None = None
diff --git a/tianshou/highlevel/world.py b/tianshou/highlevel/world.py
index 6ec7c4b..9d0572b 100644
--- a/tianshou/highlevel/world.py
+++ b/tianshou/highlevel/world.py
@@ -12,6 +12,8 @@ if TYPE_CHECKING:
 
 @dataclass
 class World:
+    """Container for instances and configuration items that are relevant to an experiment."""
+
     envs: "Environments"
     policy: "BasePolicy"
     train_collector: "Collector"