There is often a tradeoff between the complexity of prompting and the complexity of grammars when collecting amounts. In general, we recommend resolving the tradeoff in favor of simpler prompting, especially for initial prompts (help prompts might need to be more verbose).

Specifying a number of
items (how many) This is the simplest amount to collect because it will typically be an integer amount – no need to deal with fractions or decimals, or to have to explain how to enter using DTMF (touchtone). For example:

System: “And how many widgets would you like to order?”

Note that this prompt assumes that the caller has already indicated a desire to order widgets, so the spoken emphasis would be on “how many” rather than “widgets”. If the context is strong enough, the prompt could just be, “How many?” In some special situations, the grammar might need to accept fractions, for example, if a caller wanted to sell “ten and a half shares”.

Specifying a quantity (how much)
In many languages there is a distinction between “count” and “mass” nouns (see <http://en.wikipedia.org/wiki/Mass_noun> and <http://en.wikipedia.org/wiki/Count_noun>). When asking for a number associated with a count noun, the prompt will include “how many”, as in the example above. When asking for a quantity associated with a mass noun, the prompt will include “how much”, and the associated grammars will often need to be able to recognize integers, fractions, and decimal amounts. For example:

System: “Transfer how much?”

Note that this prompt assumes that the caller has already indicated a desire to make a transfer from checking to savings. Possible responses that the grammar would need to recognize include “one hundred dollars”, “ten and a half dollars”, “forty seven dollars and twenty three cents”, and “eighty eight point fifty three”. There may also be a need to confirm ambiguous amounts. For example, if the response was “eighty eight fifty three”, the intended amount might be “$87.53” or “$8753”. The ambiguity could be resolved using back end processing (e.g., the account only has $100 in it) or specific reprompting (“Was that eighty seven dollars and fifty three cents?”).

Specifying a dollar amount
As shown in the previous section, there are many ways that someone might speak a dollar amount, and ideally currency grammars should be robust enough to recognize them appropriately. For example, the usual way that someone would say “$243.39” is “two hundred forty three dollars and thirty nine cents”, but it is also common to hear, “two hundred and forty dollars and thirty nine cents”.