Heuristic Evaluation: 10 Principles

We are utilising the ten general principles for user interface design, as outlined by Jakob Nielsen. This method has been chosen to evaluate Netbox since it allows us to utilise the below principles to analyse the usability of the user interface and identify any related problems in its design. An outline of each principle is given in italics below each heading.

1.Visibility of system status
The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.

As buttons are pressed, menu or icons are highlighted, giving the user an indication of how they are interacting with Netbox. Each function, whether it be chat, email, or internet, has a main menu through which the user enters and, each screen has identifiers that enable a user to recognise where they actually are (i.e. in chat, email, or inernet). Since we anticipated that the system would be impervious to any lag time, we did not require the use of an messages or icons conveying to the user that a particular process was for example, "loading".

2.Match between system and the real world
The system should speak the users' language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order.

Netbox's technology has always been grounded in the real world. That is, the technology is based upon that which is currently available and therefore familiar to our particular target group. The remote control for example evolved from a model based upon those traditionally available for devices such as TVs, DVDs etc, our mantra being that familiarity should be of great importance to our particular age group.Additionally, we 'stripped-down' the language used in conventional systems so as to "speak their [the users'] language", the purpose being to make navigation more intuitive.

3.User control and freedomUsers often choose system functions by mistake and will need a clearly marked "emergency exit" to leave the unwanted state without having to go through an extended dialogue. Support undo and redo.

Each screen that a user navigates through has a title at the top, indicating which area of the system they are in at any given time. Additionally, each screen also has a large, obvious "main menu" and "back" facilities. Furthermore, the remote control also has a "menu" button which, when pressed, takes the user to the main system menu.

4. Consistency and standards
Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform conventions

Each screen of the user-interface follows a standard format and offers similar functionality (see above heuristic for examples) so as to be consistent. Within each subsystem (i.e. chat, email, internet), the touchpad and keypad have standard functions. The touchpad allows navigation around screens and speech recognition has standard commands.

5. Error prevention
Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.

The addition of "exit to main menu" and "back" and other similar functions in each screen, allow users to always have control over where they wish to go and, together with screen titles (indicating their location) prevent a user from getting lost. Elimination of keypad text input (substituted with a keyboard and speech recognition) removed the major identified error from our system, so users no-longer stumbled when attempting to enter text.

6. Recognition rather than recall
Minimize the user's memory load by making objects, actions, and options visible. The user should not have to remember information from one part of the dialogue to another. Instructions for use of the system should be visible or easily retrievable whenever appropriate.

Font size for on-screen text is ideal (as deduced from questionnaire responses), icons are large and uniform throughout subsystems; dark colours are used for text to aid visual recognition of text, and icons illuminate when a user navigates to them.

7.Flexibility and efficiency of use
Accelerators -- unseen by the novice user -- may often speed up the interaction for the expert user such that the system can cater to both inexperienced and experienced users. Allow users to tailor frequent actions.

Netbox has numerous ports through which various peripherals can be connected (such as a keyboard), and the innovative web-translating software can be disabled so that experienced users can use the internet in a conventional manner. We thought this would appeal to the older generation, since it would allow their younger relatives to utilise the system, perhaps also removing the stigma from a device that may be perceived as "technology fot the older generation".

8. Aesthetic and minimalist design
Dialogues should not contain information which is irrelevant or rarely needed. Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility.

Compared to conventional systems, Netbox has a "stripped-down" user-interface geared toward basic functionality (unless some of the software is disabled, such as in the above instance). Only few options are given per page, but all of these are vital for the functionality required. The minimalistic, "geared-toward-function" design is refelected by the simplicity of the main menu consisting of only 4 main options (5, including "help")


9. Help users recognize, diagnose, and recover from errors Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution.

The simplicity of our system, as far-fetched as this may seem, renders it impervious to any software errors. Faced with major hardware errors (such as failure), the system simply shuts-down. Once of the major identified problems is that users will perhaps find it difficult to connect the Netxbox hardware. For this we provide a set of conventional instructions. This is a problem that requires further exploration. However, if a cable comes free from the device, a message and diagram will appear on the screen, directing the user to where the cable has become unplugged. This occurs even if the power cable becomes unplugged, since power will be temporarily provided by an internal battery.

10. Help and documentation
Even though it is better if the system can be used without documentation, it may be necessary to provide help and documentation. Any such information should be easy to search, focused on the user's task, list concrete steps to be carried out, and not be too large.

Netbox comes with conventional instructions and additional help available via the "Help" facility available on each screen.