User Interfaces

Good Design and User Interfaces

All programs are designed to:

• Collect INPUT data
• PROCESS data in some way
• OUTPUT the result

Graphical User Interface (G.U.I)-

Graphical User Interfaces (or G.U.I'S for short) involve the user choosing an option by pointing a mouse (arrow) at a particular icon representing the desired option. An example of G.U.I is the Microsoft Windows Desktop Environment.

The Microsoft Windows Desktop Environment. This is a G.U.I

Advantages include:

• They are far easier to use for 'beginners'. 
• They enable you to easily exchange information between software by copy and paste ('drag and drop').

Disadvantages include:

• They use a lot of memory and processing power. It can be slower to use for expert users and you are familiar to the Command Line Interface.
• They can be irritating to experienced users as simple tasks may require several operations.  

Command Line Interface-

A Command Line Interface allows the user to interact with the computer by typing commands. The computer displays a prompt; the user keys in a command, presses enter or return and the command in question will be performed. A common Command Line Interface is Microsoft Disk Operating System. (MS-DOS). 

The MS-DOS. This is a Command Line Interface

Advantages include:

• Experienced users who know the commands can work very quickly without having to find their way around menus. 
• Command driven programs do not need to run in Windows.
• They do not need the memory or the processing power of the latest computer and will often run on lower spec machines.

Disadvantages include: 

• Commands must be typed correctly and in the right order or they will not work
• An inexperienced user may find it difficult to use because of all the commands that have to be learned. 

Menu Driven Interface-

Menu Driven Interfaces display a range of various different options in the form of a menu which the user has to work through in ordered to select the desired option. They are better for beginners as they can work through the menus step by step. However, experienced users may find this time consuming. Menu Driven Interfaces are used a lot in everyday life. For example:

• Ipods/Mp3's
• Games Consoles 
• ATM's

An ATM. This uses a Menu Driven Interface

Advantages include:

• Ideal for small lists of options
• Easy for novices
• No need to learn any navigational skills

Disadvantages include:

• It can be a slow form of navigation for experienced users
• It has a limited user interface

Form Based Interface-

A type of user interface used to organize questions or options for the user so that they resemble a traditional paper form to be filled out by pointing to the fields and typing text, or by choosing from a list.

This is an example of a form based interface

Advantages include:

• Information is organised clearly
• Easy for novices to understand and use

Disadvantages include:

• Time consuming for more experienced users

Natural Language Interface-

Natural Language Interface is a type of human interface that recognizes verbs, phrases and clauses spoken by the user for selecting, creating and modifying data.  

The Iphone's Siri feature is a good example of a Natural Language Interface

Advantages include:

• The speed of the interface
• The ease of use of the interface

Disadvantages include:

• The challenge to understand a wider range of ambiguous input