Goals that designers set themsleves. these are incorperated into the product, this will ensure that the product will ultimately be usable. manual should not be required.
Effectiveness- is how well it does what we want it to do, contains features that we need.
Efficiency- is how well the system supports the user in doing certain activities i.e. in term of simplicity and speed.
Safety- does not physically harm the user. Also does not interupt the user in what they are doing.
Does not melt, erase information, become corrupt etc.
Utility- user can use the product without too much hassle. Again takes ease of use into account.
Learnability- easy to learn and quick to learn.
Memorability- easy to remember functions, activities and such like.
Design Principles
Visibility- controls, knobs, buttons should all be clearly visible to the user.
Feedback- gives user information back on what has been done or activated. Should not leave user hanging or wondering at what stage they are within the activity. can be emphasised by highlighting, animation sound etc.
Constraints- prohibiting certain actions, helps user to make less mistakes by pressing the wrong buttons. Physical constraints refer to physical objects in the real world stopping users from doing certain things. Logical constraints looks at how users relate objects in the real world with each each other. Cultural constraints involves use of technology in certain way.
Mapping- relationship between objects and signs in the real world. Includes positioning, movement and the result.
Consistency- use of similar controls for similar tasks. Consistency can be in the design (aesthetically and ergonomically), the controls and the funtcions. making a product consistent allows the user to learn it quicker and easier.
Affordance- an attribute within a product which indicates how to use it e.g. the shape of a chair affords sitting on it.
Sony Ericsson K800i phone
Usability Goals
Effectiveness- the phone has the basic functions which i needed initially e.g. making and receiving calls, making and receiving texts. It also contains many more features which make using the phone a lot more fun e.g. a 3.2 megapixel camera/video, games, calculator function, storage for music, pictures and video etc. therefore i thinks it very effective in what the user can do with it.
Efficiency- it is quick and easy to get started, user just presses the joystick to select options. To get to a certain function there are not many interfaces the user has to go through. It is kept concise and straight to the point. There is also the option to create short cuts (e.g. push joystick to the left to get to the messaging function rather than going through the main menu).
Safety- the phone is very safe to use as there are no sharp ends or loose bits (except the battery, memory and sim card which are safely concealed inside the back and side of the phone) that children may choke on. If the phone gets wet user cannot get an electric shock, although the phone will be damaged internally. The phone does crash at times but there is no loss of data or a memory wipe. The only way this phone can be harmful is if it is used physically.
Utility- there are many features that the user can utilise. However it does not the convertor function. I used to have a Nokia phone prior to this one which did have that function. It was convenient as i could make conversions on the go. It was a bit disappointing when i found out this phone did not have that.
Learnability- when I first used the phone there was a tutorial on using the phone which was simple and easy to use. All functions are shown with easy-to-recognise icons. Buttons and functions are well assigned so picking up instructions are easy for the user. If user is new and they are used to uysing a Nokia phone for example then they find it a bit frustrating to get used to.
Memorability- procedures are easy to remember as they are kept to a minimum. Use of icons helps memory e.g. a camera icon is obviously for the camera function, an envelope icon is for the messaging function.
Design Principles
Affordance- all the buttons are raised to afford pressing. The joystick is positioned in the middle and is a small cylinder sticking out, affords pushing in all directions 360 degrees. However just by looking at the joystick a user may not be able to see it affords pressing until they try it on purpose or by accident.
Consistency- the design is consistent as all Sony Ericsson phones are designed similarly. The number buttons are all the same colour, the browser buttons are all the same colour. Colour scheme is consistent; grey silver and black. Font is the same throughout the phone.
Mapping- to use the camera user turns the phone sideways; the camera functions are set just like they would be on a real camera. The ‘photo taking’ button is on the right and the zoom buttons are on the left which users are used to on standard cameras.
There are two buttons, one on the left and one on the right, at the bottom of the screen. They have a ‘dash’ icon on them. On the screen in certain activities, on the bottom of the screen there will be text e.g. on the left it would say ‘calls’ and on the right it would say ‘planet 3’. The ‘dash’ buttons actually correspond to the text on the bottom of the screen. Thus when the left button is pressed it would take the user to the calls area and when the right button is pressed it takes the user to planet 3 area.
Constraints- icons and text on buttons constrains the user from pressing the wrong button for the wrong reason. There is a flap on the side of the phone, which opens up so that the user can insert the memory card. The flap has a thin attachment which stops it from being ripped off or being separated and lost. The off button is placed on the top of the phone and out of the way. It is only raised slightly, it still affords pushing but it makes it more difficult for the user to push it by mistake.
Feedback- gives relevant feedback when an action is activated. When a message is sent, a small dialogue box comes up to show this. When a background theme is set, it also shows this with a dialogue box. when battery is low, an image of a battery dying is shown and a sound is also made.
Visibility- each button has either text or an icon on it making visible what it is used for. There are buttons on the side of the phone which also have icons on them. However how to open the phone in order to insert the battery is not visible. It has no indication on how the back part is opened. There are two buttons on either side of the voice speaker; they have no icons next to them. Only a few months ago did i realise they actually had a function which was to view photos.
