SECTION 1 _ HOW WELL IT IS DESIGNED
This section is the evaluation of how well the remote control for SONY MHC-EC55 audio system is designed.
1. high level user needs for a remote control
· BASIC FUNCTION
Customers want to be able to control the audio system from a distance and in different angles.
Customers want to get feedback from the display of the system whenever they press a button. If they fail to see any change on the display, they will assume the action haven’t been taken.
Customers want the remote control to be comfortable to hold in either left or right hand while controlling.
· AVOID ERRORS
Customers want to press each button accurately without touching any button else on the keypad.
· CORRECT ERRORS
Customers want to be able to correct the error once they make a mistake accidently.
Customers want to be able to press the main buttons in some unusual cases such as having something in their hands or having dirty hands.
2. user capabilities and characteristics
· The user is someone except for children or older adults.
· The user could be either a man or a woman.
· The user wants to listen to the radio or play a music CD with a relatively high standard sound quality. In some cases the user want to connect it to some devices.
· The user has at least one hand and doesn’t wear gloves.
3. environments of use
· The user wants to use it in private spaces like bedroom or public spaces like office.
· The user wants to use it both in the daytime and at night with lights on or off.
· The remote control should be used in the same space as the system.
SECTION 2 _ EVALUATION WITH 8 PRINCIPLES
This section is the evaluation in terms of 8 principles from The Design of Everyday Things by Don Norman. Some problems with the use of the remote control are revealed.
The remote control allows you to press any button on the front panel and change batteries from the back.
For users who have basic life experience but haven’t use an audio system before, it is easy to turn on and off the audio, play, pause and stop the CD, switch songs and control volume.
Besides these functions, users might need to read the manual to learn what the other keys do.
In other words, for normal users, what they see on the remote control are the buttons in the blue box (shown in the left picture) and something else.
The unfamiliar buttons are distracting.
The dimensions of the remote control:
5.250in x 1.875in x (0.625~0.875) in
The size allows people to hold and control with single hand with a precision grip.
The center of gravity is in the middle and to the bottom of the handgrip.
The user has to move the hand back and forth to reach all the buttons.
There is almost no difference to control with either left hand or right hand.
ANTHROPOMETRY OF CURRENT USERS
Kelvin, Male, Left-handed:
A 2.750in B 2.250in C 3.125in D 4.000in
Susan, Female, Right-handed:
A 2.750in B 2.250in C 2.750in D 3.500in
There isn’t much difference when they use the same remote control.
In the position of the hand that the remote control affords, the thumb can reach all frequently-used keys and the index finger can reach the rest area.
The size of the remote control is small and the main function buttons are centered so that the user who holds the remote control in this way can keep his wrist straight while operating.
Users who holds the remote control in the above way cannot keep her wrist straight.
The flat back of the remote control allows users to press the keys with the joints of their fingers when they have something in their hand or their hands are too dirty to touch the keys.
2. CONCEPTUAL MODEL
The user will assume the following functions exist:
1 is the power button controlling the on/off of the audio system.
4 allows to play, pause and resume.
5 allows to totally stop the whole song, switch to the previous one or to the next one and go forward or backward in the period of one song.
14 controls the volume.
3. MAKING THINGS VISIBLE
The icons on the familiar buttons are big and easy to recognize. There are simple titles related to their functions close to the buttons unfamiliar to the user. Once they have gone through the manual, they possess the full description in their mind. They will know what the button is for when they see it again.
Users can feel the little dot on the volume button to tell the position of main keys without looking at the remote control. But the buttons are not visible in the dark. There is a chance to make mistakes.
Each button on the remote control is mapping to a button on the control panel of the main set.
The mapping of the remote control is clear for users.
The user can get feedback from the display in time.
The feedback for each function is clearly addressed.
6. FREQUENCY OF USE
The way to demonstrate the frequency of use is to make the buttons in different shape and size. The most frequently used ones are slightly bigger than the infrequently used ones and are centered on the remote control. The rarely used ones are in a long horizontal shape and are far from the center area.
The power button is colored in green and is set in a pit to the corner of the panel so that the user can reach it easily.
The long horizontal buttons on both sides of the volume buttons are confusing. They are relatively rarely used but are set at the most convenient area.
7. IMPORTANCE OF USE
The most important buttons (play, pause, stop, volume increase/reduce) are designed to be both in the visual center and in the gravity center. They can be tell apart just by touching.
But they are not very easy to tell one from another. It takes practice.
8. SEQUENCE OF USE
The play, pause, stop button are arranged from left to right in the sequence of use.
The forward/backward, previous/next, volume increase/reduce buttons are put in the way according to common knowledge.
section 3 _ REDESIGN
This section is the redesign of the remote control which can keep users’ wrists straight when then operate it.
-Raised buttons in unique shapes
-Slide power button
-Infrequently used keys are colored and hidden.