Documentation for the classic Watson Assistant experience has moved. For the most up-to-date version, see Starting and ending the dialog.

Starting and ending the dialog

Learn more about how to use the nodes that are added to your dialog automatically to start and end the conversation.

When you add a dialog to your dialog skill, the following dialog nodes are added to it automatically:

Welcome: Defines how the assistant greets the user and starts the conversation.
Anything else: What the assistant says when a customer's request cannot be satisfied by any of the defined intents.

Starting the conversation

The Welcome node is defined using the welcome special condition, which is triggered when the assistant, rather than the user, starts the conversation. This happens when the integration or client application starts the session with an empty message and then waits for the assistant to greet the user, as in the following situations:

Preview for the assistant
"Try it out" pane
Web chat integration with home screen disabled

However, the Welcome node is skipped in situations when the user initiates the conversation by sending a message, such as with the Slack and Facebook integrations. It is also skipped when using the Web chat integration with the home screen enabled, because in this situation the home screen provides the greeting. (Note that the home screen is enabled by default.)

Unlike the welcome special condition, the conversation_start special condition is always triggered at the start of a conversation. You can use a combination of nodes with these two special conditions (welcome and conversation_start) to manage the start of your dialog in a consistent way.

For more information, see Special conditions.

Setting initial context

If you need to set initial context variables at the beginning of each conversation, make sure you do so in a way that works with all of the integrations you plan to use. Do not use the Welcome node to set initial context variables unless you are certain your dialog will only be accessed in situations where the welcome special condition is triggered.

A safer and more consistent approach is to always set any initial context in a node defined using the conversation_start special condition, which is always triggered. You can use this node in addition to a Welcome node that displays a greeting.

To manage the start of any conversation regardless of integration, follow these steps:

Add a dialog node above the Welcome node that is automatically added to the top of the dialog tree when you create the dialog.
Set the node condition for this newly added node to conversation_start. This node will be reliably triggered at the beginning of any conversation.
In the conversation_start node, define any default values for context variables, and call any webhooks you need to call at the beginning of every conversation.
Do not define a text response for this node. Instead, configure this node to jump to the Welcome node directly below it in the dialog tree (or whichever other node you want to process first), and choose If assistant recognizes (condition).

Screenshot of the dialog tree with a conversation_start node jumping to a welcome node below it.

This design results in a dialog that works like this:

Whatever the integration type, the conversation_start node is processed, which means any context variables that you define in it are initialized.
In integrations where the assistant starts the dialog flow, the Welcome node is triggered and its text response is displayed.
In integrations where the user starts the dialog flow, the user's first input is evaluated and then processed by the node that can provide the best response.

Ending the conversation gracefully

The Anything else node is designed to recognize the anything_else special condition, which understands when user input does not match any of the intents that are used as conditions in a dialog's nodes.

Don't delete the Anything else node.

You might not recognize its value at first, but it serves some important functions. If you did delete it, don't panic. You can add it back. Just add a dialog node to the end of your dialog tree, and add the anything_else special condition to its If assistant recognizes field.

The Anything else node provides the following benefits:

It prevents your assistant from ever going silent and failing to respond at all to your customers. The Anything else node is what enables your assistant to (if nothing else) say, I'm sorry, I didn't understand. or I can't help you with that.
The skill's analytics feature uses this node to learn about the topics that your dialog can't address. The coverage metric looks for occurrences of nodes with the anything_else condition being processed in the user conversation logs. It uses this information to determine the frequency with which your dialog is able to match user requests to intents that can address them. The node is registered by the metric if it conditions on anything_else alone or when it's used in combination with another condition, such as anything_else && #positive_feedback.

For more information about the coverage metric, see Graphs and statistics.
If you want your assistant to redirect queries to the search skill when the dialog is unable to address them, this node recognizes when it's time to initiate the search. It's when a customer's message reaches the anything_else node that the message is sent to the search skill to find a relevant answer in your configured data collections. For more information about searching for an answer, see Search triggers.

Messages that trigger search in this way are still registered by the coverage metric as messages that are not covered.