14.2 Prompt Design

After we complete the high-level call flow and the Login, Quotes, and Trading subdialogs, we begin to work on the prompting. We do this by specifying sample dialogs to cover the various dialog paths.

Here's an initial sample dialog, starting with the welcome prompt and the Login subdialog:

(1)

SYSTEM:	<audio brand> Thanks for calling Lexington Brokerage. What's your account number?
CALLER:	837620868247.
SYSTEM:	Okay. Now tell me your PIN. <pause> You can also enter it with touchtones.
CALLER:	1743.
SYSTEM:	Great.

We then continue the sample dialog in (2), assuming that this is a first-time caller:

(2)

SYSTEM:	With this system you can get quotes, place trades, access your account, and get information about your portfolio. If you ever feel lost or want more information, just say, "Help." So what can I do for you?
CALLER:	I wanna buy a hundred shares of Apple.
SYSTEM:	Okay, at what price?
CALLER:	At the market.
SYSTEM:	Confirming: You want to buy one hundred shares of Apple Computer, at the market. Good for the day. Is that right?
CALLER:	Yes.
SYSTEM:	Your order's been placed. I'll let you know when it's been filled.
. . .

Example (2) shows the system transitioning from a wide-open prompt ("So what can I do for you?") to a directed prompt ("Okay, at what price?"). This dialog also uses careful confirmation of the trade details before it is placed.

We work through a number of sample dialogs to flesh out the company-name disambiguation approach in the Quotes subdialog. First, we handle a case of two companies having the same name:

(3)

CALLER:	Sysco.
SYSTEM:	Do you want Cisco Systems or Sysco Foods?
CALLER:	Sysco Foods.

Next, we handle a case of five companies having the same name:

(4)

CALLER:	Genesys.
SYSTEM:	There are five companies with that name. Please say the company's full name.
CALLER:	Um. I'm not sure what the full name is.
SYSTEM:	<reject> Sorry, I didn't understand. There are five companies with the name you requested. When you hear the one you want, please repeat the full company name. Genesys Bioventures. <pause> Genesys Microchip. <pause> Genes…
CALLER:	Genesys Microchip.

As we work through sample dialogs for the Trading subdialog, we realize that some states will need multiple possible initial prompts, depending on the context. In (5), we enter the state that queries for the number of shares twice; the second entry is to correct a misrecognition. As you can see, the prompt wording and prosody are different the second time we enter.

(5)

CALLER:	Buy Intel.
SYSTEM:	How many shares?
CALLER:	Two hundred fifty.
SYSTEM:	And at what price?
CALLER:	At twenty-eight.
SYSTEM:	Confirming: You want to buy two hundred fifteen shares of Intel at twenty-eight. Is that right?
CALLER:	No.
SYSTEM:	Do you want to change the company, the number of shares, the price
CALLER:	The number of shares.
SYSTEM:	Okay. How many shares do you want to buy?

In a similar fashion, we create sample dialogs for many possible paths. In some sample dialogs, we will get quotes and then make a trade. In others, we will flesh out some of the error handling.

When we have a full set of sample dialogs, we get together with a colleague and read through them out loud. Upon hearing them in this conversational context, we gain some new perspective and make a few adjustments.

We then flesh out the dialog specification for the high-level call flow, Login, Quotes, and Trading, including all prompts and error handling. For each state, we try to imagine the most likely causes of problems and design error messages to recover effectively. For example, the first time there is a reject or timeout in the GetAccountNumber state, we remind callers that they can say, "I don't know"; the second time, we suggest that they key in the account number. When this part of the design is complete, we are ready to prepare for the WOZ test.