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1.2 Good and poor design 3

You wait to hear how to listen to a recorded message. But there are no further
instructions from the phone. You look down at the instruction sheet again and
read:
"2. Touch*, your room number, and #". You do so and the system replies,
"You have reached the mailbox for room 106. To leave a message type in your
password."
You type in the room number again and the system replies, "Please enter room
number again and then your password."
You don't know what your password is. You thought it was the same as your
room number. But clearly not. At this point you give up and call reception for help.
The person at the desk explains the correct procedure for recording and listening
to messages. This involves typing in, at the appropriate times, the room number
and the extension number of the phone (the latter is your password, which is differ-
ent from the room number). Moreover, it takes six steps to access a message and
five steps to leave a message. You go out and buy a new cell phone.
What is problematic with this voice-mail system?
It is infuriating.
It is confusing.
It is inefficient, requiring you to carry out a number of steps for basic tasks.
It is difficult to use.
It has no means of letting you know at a glance whether any messages have
been left or how many there are. You have to pick up the handset to find out
and then go through a series of steps to listen to them.
It is not obvious what to do: the instructions are provided partially by the
system and partially by a card beside the phone.
Now consider the following phone answering machine. Figure 1.1 shows two
small sketches of an answering machine phone. Incoming messages are represented
using physical marbles. The number of marbles that have moved into the pinball-
like chute indicates the number of messages. Dropping one of these marbles into a
slot in the machine causes the recorded message to play. Dropping the same mar-
ble into another slot on the phone dials the caller who left the message.

Figure 1 .1 Two small
sketches showing answer-
ing phone.