Policies

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viewing: 1.10.0

Policies

Configuring Policies

The rasa.core.policies.Policy class decides which action to take at every step in the conversation. There are different policies to choose from, and you can include multiple policies in a single rasa.core.agent.Agent.

Max History

One important hyperparameter for Rasa Core policies is the max_history. This controls how much dialogue history the model looks at to decide which action to take next. You can set the max_history by passing it to your policy’s Featurizer in the policy configuration yaml file.

Data Augmentation

When you train a model, by default Rasa Core will create longer stories by randomly gluing together the ones in your stories files.

Action Selection

At every turn, each policy defined in your configuration will predict a next action with a certain confidence level. The bot’s next action is then decided by the policy that predicts with the highest confidence.

Keras Policy

The KerasPolicy uses a neural network implemented in Keras to select the next action. The default architecture is based on an LSTM.

Embedding Policy

Warning EmbeddingPolicy was renamed to TEDPolicy. Please use TED Policy instead of EmbeddingPolicy in your policy configuration. The functionality of the policy stayed the same.

TED Policy

The Transformer Embedding Dialogue (TED) Policy is described in our paper. This policy has a pre-defined architecture.

Mapping Policy

The MappingPolicy can be used to directly map intents to actions.

Memoization Policy

The MemoizationPolicy just memorizes the conversations in your training data.

Augmented Memoization Policy

The AugmentedMemoizationPolicy remembers examples from training stories for up to max_history turns.

Fallback Policy

The FallbackPolicy invokes a fallback action if at least one of the following occurs: The intent recognition has a confidence below nlu_threshold.

Two-Stage Fallback Policy

The TwoStageFallbackPolicy handles low NLU confidence in multiple stages by trying to disambiguate the user input.

Form Policy

The FormPolicy is an extension of the MemoizationPolicy which handles the filling of forms.