Anais do IHC'2001 - Departamento de Informática e Estatística - UFSC

40
Welcome +
System message
“Please type in your
account #”
“Type in your
password”
“One moment”
Anais do IHC’2001 - IV Workshop sobre Fatores Humanos em Sistemas Computacionais
System User
Checking account
balance:
“Type in:
3 for investments
4 for savings account
5 for additional info
6 for last entries
9 for another account
0 for an attendant”
types in
types in
hangs up
Task GetAccountBalanceViaPhone
(Domain Information)
sequence
{
Dialog AccountNumber (Information Request)
}
Dialog AccountPassword (Information Request)
Dialog AccountBalance (Domain Information)
Dialog ServicesSelection (Selection)
Figure 1: Phone interaction for getting a checking account balance, and the
corresponding interaction specification.
One may notice that the user provides the account number, and the system does not
utter it back in order to confirm it. Instead, the information that the account number is
correct is implicit because of the password validation. This might seem a violation of the
Maxim of Quantity. However, since the rate of speech production is fast, the topic of the
conversation, which is the account number, is retained in memory as it would in normal
human conversation. In spite of this, if a user has more than one checking account at one
time, he/she may forget which account is being verified at the moment, and there is no
means for him/her to retrieve the current topic of conversation in this system; he/she would
have to start over, and pay more attention next time.
4.2 ATM System
Figure 2 illustrates the interaction that took place in the ATM system for the same task
(getting the checking account balance), and the corresponding LECI specification (to the
right). This interaction takes much longer than the previous one, with the phone-banking
system. In part, this is due to security issues (asking for the password before sensitive
information is provided), but also because there are more services available at the ATM
than by the phone-banking system, i.e. the two systems are not functionally equivalent.
One may notice how the service is chosen, by a composition of three consecutive choices,
as expressed by the ServicesSelection dialog.