Conversational components Errors

Errors

Errors occur when your Action can’t move forward because it 1) didn’t understand the user’s input, or 2) didn’t get input. Since this can happen at any time, your Action needs to have unique error handling for each turn in the conversation to help the user get back on track.

Guidelines Expand and collapse content An arrow that points down when collapsed and points up when expanded.

How your Action responds to errors can make or break the user experience. When users are unable to complete their tasks, they’re unlikely to talk to your Action in the future. One poorly handled error can outweigh dozens of successful interactions. But with good error handling, the user won’t even know an error occurred.

Keep in mind the following considerations:

Cooperation

Assume the user is being cooperative, and what they’re saying is relevant and valid. Users are just trying to accomplish something; it's your job to figure out what that is.

Transparency

Be honest and transparent when explaining why something doesn’t work.

Context-specific

Good error handling is context-specific. Even though you’re asking for the same information, the conversational context is different on the second or third attempt.

There are 3 types of errors:

Errors in human-to-human conversations

Errors in human-to-computer conversations

Imagine you’re talking to someone and...

...they don’t respond to you.

No Input

The Action hasn’t heard the user’s response, or the user hasn’t responded by the time the microphone closes.

...they say something that confuses you.

No Match

The Action can't understand or interpret the user's response in context.

...they ask you to do something you can’t do.

System error

The systems that the Action depends on for information can’t complete the task.

No Match Expand and collapse content An arrow that points down when collapsed and points up when expanded.

Why No Matches happen:

A No Match error occurs when the Action can't understand or interpret the user's response in context.

Here are a few possible causes of No Match errors.

Persona: Ibento (fake ticket-seller). User input: I wanna buy tickets to the virtual reality cinema on Wednesday at 8 PM. Spoken prompt: Sure, for how many people? New turn. User input: Uhh… let me see, there’s Sky, Roberta, umm… . Spoken prompt: Sorry, for how many?

The user doesn’t respond fully or clearly, possibly hesitating, changing their mind or not completing their sentence.

Persona: Ibento (fake ticket-seller). User input: I wanna buy tickets to the virtual reality cinema on Wednesday at 8 PM. Spoken prompt: Sure, for how many people? New turn. User input: Hey Sky, how many are coming on Wednesday? Spoken prompt: Sorry, for how many?

The user might not be speaking to the Action.

Persona: Ibento (fake ticket-seller). User input: I wanna buy tickets to the virtual reality cinema on Wednesday at 8 PM. Spoken prompt: Sure, for how many people? New turn. User input: Just me and the kids. Spoken prompt: Sorry, for how many?

The user says something relevant to the question, task, or domain, but the Action doesn’t understand it. This might occur when either the user’s response isn’t included in the recognition grammar, or it’s given in a noisy environment.

Persona: Ibento (fake ticket-seller). User input: I wanna buy tickets to the virtual reality cinema on Wednesday at 8 PM. Spoken prompt: Sure, for how many people? New turn. User input: Tell me a joke. Spoken prompt: Sorry, for how many?

The user wants to switch topics entirely.

1st level No Match (rapid reprompt):

Quickly and concisely collect the information again or in another way. The user was trying to engage, so they probably just need another chance. Do not repeat the original prompt verbatim since it will sound robotic.

Rapid reprompts typically combine an apology with a condensed repetition of the original question.

Persona: Ibento (fake ticket-seller). Spoken prompt: Sure, how many people are going? New turn. User input: Me and my crew. Spoken prompt: How many was that?

Do.

Reiterate the question quickly and succinctly.

Persona: Ibento (fake ticket-seller). Spoken prompt: Sure, how many people are going? New turn. User input: Me and my crew. Spoken prompt: Sorry, I didn’t catch that. Please tell me how many people will be going to the event.

Don’t.

Don’t dwell on or over-explain the error.

Persona: Ibento (fake ticket-seller). Spoken prompt: Alright, when’s the event? New turn. User input: I’m just taking a look. Where’s that uhh… Ah, got it. Spoken prompt: Sorry, when is it?

Do.

Combine apologies with questions.

Persona: Ibento (fake ticket-seller). Spoken prompt: Alright, when’s the event? New turn. User input: I’m just taking a look. Where’s that uhh… Ah, got it. Spoken prompt: Sorry, tell me when the event is, like “tomorrow at 9 AM”.

Don’t.

Don’t provide examples for simple responses. Avoid escalating detail in the 1st No Match prompt (exceptions below).

There are exceptions when the user could benefit from more support in the 1st No Match prompt.

Persona: Miso flowers (fake flower shop). User input: Send flowers to Priya. Spoken prompt: Which Priya? New turn. User input: Uhh… what? Spoken prompt: You’ve got 2 Priyas in your address book: Priya Patel and Priya Bakshi. Which did you mean?

Do.

Including additional information can help users respond by narrowing down their request.

Persona: Sekai (fake shoe store). User input: What kind of shoes are you looking for? New turn. User input: Something cool. Spoken prompt: Sorry, try saying a type like “sneakers”, “boots” or “Oxfords”.

Do.

Allow users more guidance when reasonable, particularly after wide-focus questions.

2nd level No Match (escalating detail):

In each context, consider why the user might be having difficulty. Then, in the reprompt, include additional support in the form of options, examples, or visual information. Examples are particularly effective, since they give the user an implicit model of what to say and how to say it, without drawn-out explanations or instructions.

Persona: Sekai (fake shoe store). Spoken prompt: Sure, in what size? Display prompt: Sure, in what size? New turn. User input: Large. Spoken prompt: Sorry, what size? Display prompt: Sorry, what size? New turn. User input: Large. Spoken prompt: Sorry, our shoes come in sizes 6 through 11, including half sizes. Here’s our size chart with some more info. Now, what size do you want? Display prompt: Sorry. Here’s our size chart. What size do you want? Visual: Paginated list card showing women’s shoe size conversions for US / EU / Asia.

Do.

Try to be helpful, providing your best guess at relevant information that can be useful.

Persona: Sekai (fake shoe store). Spoken prompt: Sure, in what size? Display prompt: Sure, in what size? New turn. User input: Large. Spoken prompt: Sorry, what size? Display prompt: Sorry, what size? New turn. User input: Large. Spoken prompt: Sorry, what size do you want?</p><p> Display prompt: Sorry, what size do you want? Visual: None.

Don’t.

Don’t repeat the same thing over and over. The user is stuck and needs additional guidance.

Persona: Geek num (fake game). Spoken prompt: Howdy! I can tell you facts and trivia about almost any number. So, what number do you wanna know about? New turn. User input: My favorite number. Spoken prompt: Sorry, what number? New turn. User input: Umm… how about… . Spoken prompt: Sorry, what number would you like to hear fun facts about?

Do.

Talk to the user like you’re having a human-to-human conversation.

Persona: Geek num (fake game). Spoken prompt: Howdy! I can tell you facts and trivia about almost any number. So, what number do you wanna know about? New turn. User input: My favorite number. Spoken prompt: Sorry, what number? New turn. User input: Umm… how about… . Spoken prompt: Sorry, tell me what number you’d like me to tell you fun facts about. For example, you might say 42 or 101. Go ahead.

Don’t.

Make sure that you’re not being condescending!

Max No Match:

End the conversation after 2 No Match collection attempts, to avoid further user frustration.

Persona: Geek num (fake game). Spoken prompt: This seems beyond my expertise, so let’s stop here. Goodbye.

Do.

End the conversation gracefully when there’s nothing you can do to help the user.

Persona: Geek num (fake game). Spoken prompt: I’m only an expert on numbers right now, but I’m always learning.

Don’t.

Vague promises, particularly when you don’t know what the user has asked for, are unhelpful and erode user confidence.

Let users know if there are other ways they can complete their task.

Persona: Sekai (fake shoe store). Spoken prompt: Sorry, I’m still having trouble, so you may want to visit our website instead. Bye for now.

Do.

Next steps can be better than nothing, even when the user has to do it themselves.

Persona: Sekai (fake shoe store). Spoken prompt: Sorry, I didn’t understand that either. Please try again in a few minutes.

Don’t.

Don’t recommend trying again in a few minutes or on another device if it’s unlikely to fix the issue.

No Input Expand and collapse content An arrow that points down when collapsed and points up when expanded.

Why No Inputs happen:

The Action hasn’t detected a response from the user, because the user:

  • hasn’t said anything while the microphone was open
  • hasn’t spoken loud enough

Here are a few possible causes of No Input errors.

Persona: Ibento (fake ticket-seller). User input: I wanna buy tickets to the virtual reality cinema on Wednesday at 8 PM. Spoken prompt: Sure, for how many people? New turn. User input: Silence. Spoken prompt: How many people are you buying tickets for?

The user left the room, is distracted, or maybe changed their mind.

Persona: Ibento (fake ticket-seller). User input: I wanna buy tickets to the virtual reality cinema on Wednesday at 8 PM. Spoken prompt: Sure, for how many people? New turn. User input: Doorbell ringing and dog barking. Spoken prompt: How many people are you buying tickets for?

There’s no speech, just noise.

Persona: Ibento (fake ticket-seller). User input: I wanna buy tickets to the virtual reality cinema on Wednesday at 8 PM. Spoken prompt: Sure, for how many people? New turn. User input: Checks email for who responded that they could attend. Spoken prompt: How many people are you buying tickets for?

The user is thinking or unsure about how to respond.

Persona: Ibento (fake ticket-seller). User input: I wanna buy tickets to the virtual reality cinema on Wednesday at 8 PM. Spoken prompt: Sure, for how many… User jumps in with input: Six. Spoken prompt continues: ...many people? New turn. User input: Silence. Spoken prompt: How many people are you buying tickets for?

The user spoke before the mic opened.

1st level No Input:

When writing No Input prompts, assume that the user hasn’t heard the question.

Persona: Geek num (fake game). Spoken prompt: I’ve got 3 areas where you can learn more about 42. There’s Math and prime numbers, Ancient Egyptian religion, or 42 recipes with 42 ingredients. Which one do you want to hear more about? New turn. User input: Silence. Spoken prompt: I can tell you about Math & prime numbers, Ancient Egyptian religion, or 42 recipes with 42 ingredients. Which one interests you?

Do.

Repeat the question (by rephrasing) in a similar and concise way.

Persona: Geek num (fake game). Spoken prompt: I’ve got 3 areas where you can learn more about 42. There’s Math and prime numbers, Ancient Egyptian religion, or 42 recipes with 42 ingredients. Which one do you want to hear more about? New turn. User input: Silence. Spoken prompt: Sorry, I didn’t hear you. Which did you want?

Don’t.

Don’t say “I didn’t hear you”, because it’s likely the user hasn’t said anything. And don’t assume the user heard the first question or remembers the options that were offered.

There are exceptions when the user could benefit from more support in the first No Input prompt.

Persona: Miso flowers (fake flower shop). User input: Send flowers to Priya. Spoken prompt: Which Priya? New turn. User: Silence. Spoken prompt: Do you want to send flowers to Priya Patel or Priya Bakshi?

Do.

When there’s a good chance the user might be stumped, see if you can provide more support.

Persona: Sekai (fake shoe store). Spoken prompt: What kind of shoes are you looking for? New turn. User input: Silence. Spoken prompt: We’ve got “sneakers”, “boots” and “Oxfords” to name a few. What kind of shoes do you want?

Do.

Users might not respond to a wide-focus question because they don’t know what they can say. So give them some options.

If information is not required, then move on to the next step in the dialog.

Persona: Miso flowers (fake flower shop). Spoken prompt: Would you like to include a comment for the delivery person? New turn. User input: Silence. Spoken prompt: You can add it later if you’d like. Now, let’s confirm your order… .

Do.

Continue to the next step if the information isn’t required. However, make sure to not penalize the user, e.g., by skipping over something perceived as important or interesting without an opportunity to provide it later.

2nd level No Input:

Give users one more opportunity to respond before exiting.

Persona: Ibento (fake ticket-seller). User input: For 2 adults. Spoken prompt: Ok, 2 adult tickets. Should I buy them now? New turn. User input: Silence. Spoken prompt: Do you still want me to buy 2 adult tickets?

Do.

Restate the question to give the user one more chance to respond.


Max No Input:

To avoid pestering the user, end the conversation after 2 No Input collection attempts.

Persona: Geek num (fake game). Spoken prompt: It seems like you’re done geeking out about numbers with me, so let’s stop here.

Do.

End the conversation gracefully when the user stops engaging.

Error counters Expand and collapse content An arrow that points down when collapsed and points up when expanded.

Users should experience no more than 3 No Input or No Match errors in a row, after which your Action should play the appropriate max error prompt and exit the conversation.

Good error handling is context-specific. Even though you’re asking for the same information, the conversational context is different on the second or third attempt. In order to play the right error prompt for the context, you’ll need to keep track of how many, and what type of, errors have occurred.

Follow this flowchart to determine which error prompt to play. Note that every time you open the mic, there’s the potential for a No Input or No Match error to occur.

This is a flowchart that helps determine which error message prompt to play depending on the error type and how many times it has happened during the conversation. The two types of errors are No Input and No Match. If the same error type has occurred two turns in a row, the Assistant should play a 2nd level error prompt. However, if one error type (such as a No Input error) is followed by a different error type (such as a No Match error), the appropriate 1st level error prompt should play because it’s the 1st time that error has occurred during the conversation. After 3 turns, Assistant should play either a Max No Input or Max No Match prompt accordingly.

Flow chart to determine which error prompt to play.

System errors Expand and collapse content An arrow that points down when collapsed and points up when expanded.

System errors occur when the user was understood correctly, but the systems your Action depends on for information either can’t complete the task or fail due to technical reasons. Some common scenarios include:

  • System failure (the system is unresponsive or returns a general error—e.g., the light will not turn on, the database is unavailable)
  • Invalid request (e.g. the user tried to make an appointment in the past)

Evaluate every system your Action depends on and account for all possible errors that could be encountered. Where possible, provide the reason and possible next steps in a way that’s transparent, honest, and helpful.

Persona: Miso flowers (fake flower shop). Spoken prompt: I can’t reach your preferred florist right now to place your order. Should we wait a few minutes and try again, or order from another florist?

Do.

Try to be transparent without being overly technical. See if there are any next steps you might offer.

Persona: Ibento (fake ticket-seller). User input: Get me tickets to Google I/O. Spoken prompt: Tickets to Google I/O are only available via invitation or by applying to the ticket drawing. Is there another event you’re interested in?

Do.

Try to provide feedback on how the request was invalid and educate the user where possible.