• knowledge of issues related to graphical user interfaces,
• familiarity with the Macintosh and HyperCard,
• clarify coursework requirements.

• WIMP interfaces (see notes for week 2),
• Icons,
• Direct manipulation,
• Metaphors,
• WYSIWYG.

Icons

When an interface is described as iconic the emphasis is placed on the design and interpretation of icons. Some of the issues involved in the design of icons are: perception, representation (the use of symbols, depictions of referents, metaphors and so on), the functions of representations (such as identifying, indicating and classifying), discrimination between icons within groups and interactions involving icons. The figure below shows eight states of the Macintosh's Wastebasket icon:

• distance - this is the gap between what users think and what they do and perceive.
• semantic directness - the distance between the users' thinking and the forms of expression/interpretation.
• articulatory directness - the distance between the forms of expression/ interpretation and what users have to do to execute a command and evaluate its execution.

It is easier to talk of direction manipulation interactions than direct manipulation interfaces. This is because directness is an effect experienced by users rather than a property of an interface. Nevertheless, interfaces can be designed to increase the likelihood that users will experience the effect of direct manipulation. A design that permitted document icons to be dragged to a wastebasket icon would offer strong support for direct manipulation, but dialogues in which iconic buttons were clicked to turn options on and off would probably be less direct (and comparable with making menu selections).

Here is an example of some extremely mixed metaphors:

I'm in a cleft stick because my flow-charting is rusty. I'll try to hammer out the problems but they bristle with difficulties and I think I've bitten off more than I can chew.

The term metaphor comes from the Greek word Phorein which means ferrying. A metaphor conveys meaning with a direct comparison. For example, the phrase cloaked in mystery is used to indicate concealment by making a direct comparison with a cloak's ability to conceal.

The Star's (see week 2 notes) desktop metaphor was adopted to provide a familiar conceptual model of the interface - so that users could conceive of their actions as comparable with using a desk. The designers of the Star hoped the desktop metaphor would "make the electronic 'world' seem more familiar, less alien, and require less training". The Macintosh desktop contains items found in offices (such as, wastebaskets, folders and documents) and in some respects these items can be used in ways that parallel their use in offices (such as, putting documents in folders or in the wastebasket).

Other examples of metaphors employed in interface design are: control panel displays, paintboxes or palettes, the Rehearsal World's theatre metaphor and the Alternate Reality Kit's physical world metaphor.

WYSIWYG

The term WYSIWYG (pronounced "whizzy wig") relates the screen display (what you see) to printed output (what you get). The term is usually applied to text editors in which the screen display represents a sheet of paper. The designers of the Star wrote that, "The first powerful WYSIWYG editor was Bravo, an experimental editor developed ... at the Xerox Palo Alto Research Center". The significance of WYSIWYG is that it enables users to manipulate concrete representations and to avoid the mental computations involved in bridging the distance between the display and final output. An alternative to a WYSIWYG text editor would be one in which texts contain embedded commands to format printed output and in which the screen display shows the commands rather than the effects of the commands.

• mixed input dialogues - change
• when more than one dialogue style is available - choice
• dialogue and alert boxes
• program visualisation, visual programming and example-based programming
• associated with: hardware, animation, hypermedia, multimedia, Smalltalk, CAD and desk-top publishing

Practical section: Final part of introduction to Macintosh and HyperCard

• use a mouse to select - also to double click, SHIFT+click and click-and-drag,
• run Macintosh applications, save to your own disc, remove unwanted files,
• build simple HyperCard stacks with backgrounds, cards, buttons and text fields,
• link cards using buttons and the Link to: option (in Button info option),
• issue HyperTalk commands using the HyperCard message box (Apple+M keys),
• alter userlevel (1 to 5). Note: the keyword userlevel has no space,
• find the scripts for HyperCard objects (see last exercise in HyperCard introduction sheet),
• change icon shapes for buttons and change button names,
• draw graphics on cards and backgrounds.

• cut and paste text and graphics - within a HyperCard stack, between HyperCard stacks and from other Macintosh applications,
• create effects (Effects option in Button info option in Objects menu) when buttons are used to move between cards e.g. dissolve, checkerboard,
• compact a stack (File menu) before ending a HyperCard session.

• Compact your stacks, remove unwanted files from the hard disc and shut down the system using the Shut Down option in the Special menu (from Finder/desktop).

Coursework Details (supplement to half-unit guide)

You are expected to hand in a report describing a system you have built using HyperCard.

Report

• what the system can do,
• how it can be used,
• forms of usage,
• potential usability problems,
• decisions made in the process of designing the interface,
• the dialogue styles employed.

System

You choose the system and the degree of difficulty of the implementation. The report should not include details of the programming, but it should describe the interface in detail.

• a simple game: e.g. Noughts and Crosses, Towers of Hanoi or Missionaries and Cannibals,
• a computer dating service,
• a means of presenting and selecting information.

• The choice relates to the type of interface and dialogue style.
• The change can be achieved by switching between HyperCard's cards - or with HyperTalk scripts.

• if you do not assess the process of interface design during the design your report will have little substance,
• if you duplicate substantial amounts of existing work (your own or someone else's) you will receive no marks for the report (or, in exceptional circumstances, a minimum pass mark). This does not include previously existing material that you type in, draw, scan and/or cut and paste yourself - e.g. Clip Art, book texts and illustrations.