Do Not Try to Address All Possible Responses

When developing custom grammars, avoid including all possible words that a caller could speak. Instead, limit the words to the ones that callers most commonly use. Small grammars provide more accuracy than large grammars. Grammars that contain all possible words do not provide any benefit if most those words are rarely or never spoken.

Following are some guidelines for determining what words to include in your custom grammars.

Ensure that prompts are guiding the caller to a limited set of responses

While this task is not related to the actual development of grammars, it is relevant as prompts influence what responses callers speak. For example, if you want to know if a caller is calling from a business or a residence (a simple choice), the prompt provides those choices, as shown in the following example:

Are you calling from a residence or a business?

For this prompt, callers likely response with residence or business.

If the prompt does not provide choices, the responses could vary drastically:

From where are you calling?

Does this prompt expect a geographical location, a social location (home, office), or some other information? This vague prompt can cause any number of responses:

• New York

• In my car

• From my house

• ABC Company

• From my couch

• My cell phone

• The corner of 10^th and Main

While you had an idea of the responses you wanted, failure to consider how callers perceive the prompt can require large, complex grammars to account for the various types of responses that they provide. Even with those large, complex grammars, you still may not receive the simple information that you seek: business or residence.

Avoid defining all possible synonyms

Synonyms are different words that have the same or similar meaning. Using the example from the previous section where the expected responses are residence or business, do not enter all of the possible words that have similar meaning as the expected responses. The following table displays some examples of synonyms for residence or business:

If you cannot provide choices in your prompts, ensure that your grammars only contain the most common responses to the prompt. Do not include words that are rarely spoken in the responses to a prompt unless you are tuning grammars and are testing optional words to increase accuracy.

Focus on expected responses to the prompt

Your custom grammars should contain words that relate to a prompt only. For example, if a caller navigated to a prompt of Please say the digits of your account number, your grammar should not attempt to cover the rare instance of a caller saying, I just want to talk to a live person. If you enable the grammar to recognize these words in responses to this prompt, you would need to include those words in all responses to all prompts. This mistake increases your grammars needlessly, which results in lower overall recognition accuracy.

The purpose of your Interactive Voice Response (IVR) system is to enable callers to navigate menus by speaking responses to prompts, not to simulate an artificial intelligence that can process and act on any speech.