Understanding the memory of your bot (slots)

The slot is the memory of the chatbot. The slot is represented as a key-value pair, such as city: New York. It records the key information from conversations. The key information can come from a user's input (intents and entities), or from backend systems (for example, the result from a payment action: success or failure). Normally, the information is crucial for the flow of the conversation and will be used by the dialogue management system to predict the next action.

Let's take an example. In a simple application of a weather forecast, the information of location and date is key for the dialogue management system to decide the next action. If the system finds either the location or date missing, it will ask users for the corresponding information until both are present. Then the system will start to query some weather APIs.

Here, the system only cares about whether the location and date slots are filled. It does not care...