Oracle Digital Assistant: Strategies for Escaping the Validation Loop

Transcription

1 Oracle Digital Assistant TechExchange Article. Oracle Digital Assistant: Strategies for Escaping the Validation Loop Frank Nimphius, February 2019 Dialog flows in Oracle Digital Assistant intelligently guide users through a conversation to complete a task or request. Users may have different experiences with bot interactions. Although the bot designer's goal is to make the conversation as natural as possible to humans, there still is a possibility of users getting stuck. One reason for users to get stuck is when they don't know how to provide a valid answer to a bot question. Another reason is that the bot user changes his mind and wants to continue with a different task or request. Often it is the validation loop implemented on a dialog flow state that makes the bot appearing stubborn and not letting users out. In this article I explain Oracle Digital Assistant features and implementation strategies for you to use in your skill design to keep users unlocked. Oracle Digital Assistant TechExchange 1

2 VALIDATION LOOPS AND WHERE THEY ARE COMING FROM... 3 ROUTING CONSIDERATIONS... 4 STRATEGIES DISCUSSED IN THIS ARTICLE... 4 USING THE "CANCEL" ACTION TRANSITION... 4 HANDLING INVALID USER INPUT... 6 DISPLAY CONDITIONAL PROMPTS... 6 DISPLAYING CONDITIONAL PROMPTS USING COMPOSITE BAG ENTITIES... 7 CONDITIONALLY DISPLAY A LIST OF VALUES... 7 DISPLAY A CANCEL OR HELP BUTTON... 9 USING WEB FORMS CONCLUSION DOWNLOADS

3 Validation loops and where they are coming from Skills in Oracle Digital Assistant allow you to define context variables of primitive data type and of entity type. Entity types can be any system entity, which includes DATE, MAIL and RegularExpression, and custom entities, which you create for a specific use case (e.g. a list of airports). The benefit of context variables that are of an entity type is that the dialog flow state that references them is skipped if the entity value could be extracted from the user input message using natural language processing. Another benefit of entity based context variables is that the value provided by a user is validated against the entity. So when asked for providing a destination airport, a user could answer "I like a pizza", which of course is not a valid airport anywhere in this world. The entity doesn't recognize "I like a pizza" as a valid value and thus the user interface component doesn't accept the provided value. Figure 1: Validation loop when user enters a value that does not pass entity validation By default, when an input component cannot validate a user input, it does not transition to a next state in the dialog flow but continues challenging the user for a valid input. Here is where your conversation design comes into play telling the dialog flow state what to do and how to continue after a failed user value input. Note: using context variables that are of entity type actually do more than just validation. In fact it performs entity extraction. For example, if you are prompted for a date by an input component state that references a variable of type DATE (as system entity) and you input "I think I want to go tomorrow", then this is considered a valid entry as it contains "tomorrow" which gets extracted by the entity. Similar you could have said "Sure, what about June 3 rd 2010". Again, for as long as the user input contains a valid entity value, it's getting extracted. It would be wrong not to use entity-based variables only to avoid the validation loop. 3

4 Routing considerations Oracle digital assistant routes incoming messages from the messenger channel to one of its configured skills. If, in a flight booking skill bot, a user types "I like a pizza" when asked for a destination airport then this is considered invalid by the current dialog flow state. In this case dependent on the digital assistant routing configuration the digital assistant evaluates other skills for the message. If a skill is found then the user can decide to temporarily suspend the current skill and to continue with another skill. When the other skill completes, the user has the option to resume the interrupted flow, in which case the user still needs to provide a valid data input for the dialog flow state. If no candidate skill is found for the user entered message then immediately the user is prompted again to provide a valid input. Strategies discussed in this article Strategies depend on circumstances. This article discusses the skillbot capabilities that you can use to handle failed user input. The claim is not to provide a list of all possible possibilities, but to provide you with enough information to implement your own conversation design that handles failed user input as necessary for a use case. The strategies explained in this paper include Using the cancel transition to exit the validation loop after a defined number of failed input attempts Display a different prompt after a failed input For an input text component, show a list of allowed values after a failed input attempt Keep the user in the validation loop but show a help or cancel button for the user to exit the loop. And of course, there can be other buttons as well. Use web forms for structured data input Using the "cancel" action transition All input components in Oracle Digital Assistant have a maxprompts property, which is not set by default (in which case it is set to an infinite number). Setting the maxprompts property to a numeric value defines the allowed number of failed input attempts before the cancel action transition is followed. For example, setting the maxprompts property to 2 allows the user two failed input attempts before navigation happens to the state mapped in the cancel action transition. Note: If the cancel transition is not defined for a dialog flow state, then navigation follows the next transition (if defined) or the empty transition, which may cause more grief than the validation loop if not intentionally implemented this way. If you set maxprompts to 1, then the cancel transition is immediately followed after the first failed user input attempt. Thus, the combination of maxprompts property and cancel action is a solution to escape the validation loop. Figure 2 shows a state with an associated System.List component. The maxprompts property is set to 1 and the cancel transition is set to a state that is setup to handle the failed user attempt. In the example, the handlemaxpromptsexceed state prints the user provided input in a message. However, it is possible to navigate to any state in a dialog flow, not just a print state. 4

5 Figure 2: maxprompts property value set to 1 and cancel transition defined Figure 3 shows the above code in the embedded conversation tester of a skillbot. Figure 3: Runtime behavior of the configuration in figure 2 5

6 Note: When using the maxprompts property and cancel transition, then the entity based variable referenced by the input component is not updated with the invalid string entered by the user. To access the user input message, you use the following expression ${system.message.messagepayload.text}, which is also shown in Figure 2. Handling invalid user input The best way to handle failed user input is to assist the user to either provide a correct input value or to leave this part of the conversation. For this, you need to set the maxprompts property to a value higher than 1, so the cancel transition is not immediately followed in response to an invalid user input. If, for example, a user doesn't manage to provide a valid input message within 3 attempts, then it is fair enough to assume that he doesn't know better and that he needs help. In this case it is best to leave the validation loop and follow the cancel transition. Possible help options include to provide help using conditional prompts to help with a list of values display a cancel or help button Display conditional prompts The dialog flow in a skillbot manages a system variable, system.invaliduserinput, to track failed user input. By default, when entering a dialog flow state, the variable is set to false. It is set to true the first time a user provides an invalid input. As a bot designer you can use the system.invaliduserinput variable to e.g. show a different prompt after a failed input attempt. Figure 4 shows a list component state that has the maxprompts property set to 3. After the first failed input attempt, the part of the prompt that is enclosed by the <#if> </#if> Apache FreeMarker directive gets displayed to guide the user. If this is not enough, then, after the 3 rd failed input attempt, the cancel action transition is followed. Figure 4: Conditional prompt after failed user input 6

7 Figure 5 shows the dialog flow code shown in figure 4 in the skillbot conversation tester. Figure 5: Runtime view of BotML code in Figure 4 Displaying conditional prompts using Composite Bag Entities If you are working with composite bag entities and resolve them with the System.ResolveEntities or the System.CommonResponse component, then you still can set a different prompt after a failed user input. However, setting the prompt is on the entity itself and not on the component. Conditionally display a list of values When using the System.CommonResponse component, you can also use the visible property of a response item to show an extra prompt or to provide help. For example, you could show a list of values when the user failed to provide a valid input value (Figure 6). 7

8 Figure 6: Displaying a list of values after a user failed to provide a valid data input Figure 7 shows the BotML code of the bot response shown in Figure 6. The System.CommonResponse component actions is conditionally shown and renders a list of value. For this, the visible property is set to an Apache FreeMarker expression that returns true when a user failed to provide a valid data input. Note: The maxprompts property in Figure 7 is set to 2, which means that if the user fails to provide a valid data input after the list of values is displayed, the cancel action transition is followed. Figure 7: BotML dialog flow state definition of runtime behavior shown in Figure 6 8

9 Display a cancel or help button Another option to assist a user is to display a help or cancel button when the user failed to enter a valid data input. The user can then decide to continue trying or to use one of the buttons. Like the conditional list-of-values in the previous section, this option is best implemented using the System.CommonResponse component. Figure 8: System.CommonResponse component that displays a cancel and help button upon invalid user input Figure 8 shows the BotML code of the bot response shown in Figure 9 above. The System.CommonResponse component global actions element is used to display a help and a cancel button. As with the list-of-values and the changed prompt, the buttons are displayed after a failed input attempt. You can implement this using the visible property with an Apache FreeMarker expression as used in the example before, or with the oninvaliduserinput property. 9

10 Figure 9: Displaying a help and cancel button for users to escape the validation loop Using web forms Not all users are experienced bot users and not all use cases are a perfect match for the conversational channel. Ideally, user interactions on the conversational channel should be simple and short. However, if business requires lot of data to be entered then quickly using the conversational channel becomes cumbersome. Figure 10 shows a travel booking scenario in which a user fails providing the correct data input. This could be because the user is unexperienced in working with messengers, or because he just doesn't know the data to put in. Figure 10: Using a web form to assist users to provide a correct data input, or to correct previously entered data 10

11 In Oracle Digital Assistant, bot conversations can reach out for web forms to display in a web view. This allows to display input forms for structured data input, as well as specific user interface components like date picker or radio groups that don't exist in messengers. Once done with a form, the user is directed back to the bot conversation while the provided information is passed to the bot without displaying in the messenger's message history. The latter makes the web form a viable solution for all sensitive data input requirements. Building bots with Oracle Digital Assistant provides two options for you to integrate web forms to your bot conversations: The System.WebView component allows you to integrate remote web applications you built with your favorite programming tools like Oracle Jet or Oracle Visual Builder Cloud Service (VBCS). The bot calls a remote REST API to obtain a call URL that it then launches along with a callback token. The callback token is what the remote web application uses to return data to the bot. Using the System.WebView component you are in complete control over the web form fields and the form behavior. The System.Interactive component invokes Instant Apps, which is an easy to use declarative web forms design time and runtime environment built into Oracle Digital Assistant. Instant Apps provide you a rich set of user interface components as well as event triggers to perform actions and page navigation. The difference between Instant Apps and a custom web application accessed through System.WebView is that you don't control all aspects of the web application. Using a web view in a bot user interaction you can conditionally display help buttons on a dialog that lead users to a form for structured data input that helps them out of a situation in which they don't know how to proceed or where the amount of data they need to provide prohibits the user of the conversational channel from a user experience perspective. Conclusion Good conversational design aims for simplicity. Design often suffers from a technical mindset that assumes that users are not what they are. Conversational design should consider failure and allow users to recover with ease. This could be through help provided on the individual dialogs or through integration with human agents or web forms. This article showed you implementation solutions that help you handling invalid user input so your bot users remain unlocked and happy. Downloads You can download the sample bots used in this article from the Oracle TechExchange blog - Entity validation loop example showing maxprompts property and cancel transition - Common Response component that displays help buttons - Non-entity based list variables and textreceive action 11