Tutorial 4 - Usability Tools

Within this next piece of work I will be discussing Usability Goals and Design Principles in relation to my mobile phone, the Samsung E250.

Usability goals

When looking at the usability goals, I see that the designers have followed these really quite well. The first usability goal is effectiveness. This means that the product needs to be able to do what it is supposed to. As my phone allows me to make phone calls and send text messages as well extras as take photos, record videos and listen to music or the radio. This shows that my phone has a range of features that the user needs (phone calls and text messaging) as well as others that they would now expect (camera, mp3 player)

The second goal is efficiency, this means being able to use the features as simply and as quickly as possible. The designers have definitely considered this by allowing you to customise a shortcut menu to access the features you use the most. There other shortcuts available like a recent contacts list for sending texts or phoning the people you speak to the most.

The designers would have had to follow the third goal which is safety, because if they hadn’t the product would not have been released. Utility is well linked to effectiveness and efficiency, as already mentioned the phone has a range of features that are easily used.

The learnability of the phone is very good as they follow certain standards set within the phone world, with to menu buttons a centre select button, a green phone to make or answer a call and a red phone to end/cancel a call. This is also linked in with the memorability

The last usability goal is memorability, and the memorability of the phone is very good the interfaces and navigation follow the same suit so after you have learnt how to use the phone you are unlikely to forget how to use it.

Design Principles

Also the designers would have also used the design principles put forward by Norman (1988), visibility, feedback, constraints, mapping, consistency and affordance.

Visibility has had to have been considered as all the buttons are labelled and so are the slots on either side of the phone for a memory card and for the battery charger/headphones. Also I clearly know when I have received a sms message, voice mail, or phone call as it is visible on the screen.

Feedback is related to the concept of visibility. Feedback is definitely a key concept in mobile phone design. On my phone I know when I’ve pressed a button because of a keypad tone; I know I am making a phone call because it shows me on screen. If I’ve taken a photo a shutter sound will be made. These are just a few examples of feedback that is used within my phone.

Constraints meaning to restrict what a users can do. There are three types of constraints physical, logical and cultural. The designers have included some physical constraints on my phone, examples include the shape and size of the battery charger/headphone slot means they are the only things that can be inserted into that slot, its the same with the memory cad slot and the battery in the back. There are also logical constraints on my phone by the fact that the selection buttons are matched up with the options they control on the screen. And the cultural constraints are the green phone for ring/answer, the red phone for end/reject call, the icon for power and the mute icon for silent mode.

Mapping can also be linked with constraints as the selection buttons are mapped to the actions that appear above on the display.

My phone also includes consistency as every menu is laid out in the same way and your actions for navigation are all the same as well. Keeping navigation consistent. All volume controls link back to the same volume control on the side keeping it consistent..

Affordance is something the phones design includes as well as the slide up top half is something people intrinsically know what to do and its the same with the buttons people know and feel that they need to push them.