ISElective1_CM8

ISElective1_CM8

concerned with developing a conceptual model that captures what the product will do and how it will behave,

Conceptual

is concerned with details of the design such as screen and menu structures, icons, and graphics.

Physical

Two distinct circumstances for designs

(1) starting from scratch, and (2) modifying an existing product

a limited representation of a design that allows users to interact with it and to explore its suitability.
something like a scale model of a building or a bridge, or maybe a piece of software that crashes every few minutes. can also be a paper-based outline of a screen or set of screens, an electronic "picture," a video simulation of a task, a three-dimensional paper and cardboard mockup of a whole workstation, or a simple stack of hyperlinked screen shots.

Prototypes

refers to the level of detail and functionality included in a prototype.

Prototype Design fidelity

one that does not look very much like the final product. This kind of fidelity uses materials that are very different from the intended final version, such as paper and cardboard rather than electronic screens and metal.

low-fidelity prototype

often used in conjunction with scenarios. Consists of a series of sketches showing how a user might progress through a task using the device being developed.

Low Fidelity: Storyboarding

many people find it difficult to engage in this activity because they are inhibited about the quality of their drawing. Devise own symbols and icons for elements you might want to sketch, and practice using them. Simple boxes, stick figures, and stars are acceptable.

Low Fidelity: Sketching

Is used quite commonly when developing websites. Each card represents one screen or one element of a task. In user evaluations, the user can step through the cards, pretending to perform the task while interacting with the cards.

Low Fidelity: Prototyping with Index Cards

This low-fidelity prototyping assumes that you have a software-based prototype. In this technique, the user sits at a computer screen and interacts with the software as though interacting with the product. The computer is connected to another machine where a human operator sits and simulates the software's response to the user.

Low Fidelity: Wizard of Oz

uses materials that you would expect to be in the final product and produces a prototype that looks much more like the final thing.

High-fidelity prototyping

providing a wide range of functions but with little detail

horizontal prototyping

providing a lot of detail for only a few functions

vertical prototyping

involves evolving a prototype into the final product If taken, the prototypes should be subjected to rigorous testing along the way

Evolutionary Prototyping

Uses the prototypes as stepping stones towards the final design •in this, prototypes are thrown away and the final product is built from scratch

Throwaway Prototyping

concerned with transforming the user requirements and needs into a conceptual model. Description of the proposed system in terms of a set of integrated ideas and concepts about what it should do, behave, and look like, that will be understandable by the users in the manner intended.

Conceptual design

involves considering more concrete, detailed issuer; of designing the interface, such as screen or keypad design, which icons to use, how to structure menus, etc.

Physical Design

s Shneiderman's eight golden rules of interface design: For example, in every screen have a 'File' menu in the top left-hand corner. For every action that results in the loss of data, ask for confirmation of the action to give users a chance to change their minds.

Shneiderman's eight golden rules of interface design: Strive for consistency

s Shneiderman's eight golden rules of interface design: For example, in most word-processing packages, users may move around the functions using menus or shortcut "quick keys," or function buttons.

Shneiderman's eight golden rules of interface design: Enable frequent users to use shortcuts.

s Shneiderman's eight golden rules of interface design: Instead of simply saying "Error 404," make it clear what the error means: "The URL is unknown." This feedback is also influenced by the kinds of users, since what is meaningful to a scientist may not be meaningful to a manager or an architect.

Shneiderman's eight golden rules of interface design: Offer informative feedback.

Shneiderman's eight golden rules of interface design: For example, make it clear when an action has completed successfully: "printing completed."

Shneiderman's eight golden rules of interface design: Design dialogs to yield closure.

Shneiderman's eight golden rules of interface design: It is better for the user not to make any errors, i.e., for the interface to prevent users from making mistakes. However, mistakes are inevitable and the system should be forgiving about the errors made and support the user in getting back on track.

Shneiderman's eight golden rules of interface design: Offer error prevention and simple error handling.

Shneiderman's eight golden rules of interface design: For example, provide an "undo" key where possible.

Shneiderman's eight golden rules of interface design: Permit easy reversal of actions.

Shneiderman's eight golden rules of interface design: Users feel more comfortable if they feel in control of the interaction rather than the device being in control.

Shneiderman's eight golden rules of interface design: Support internal locus of control.

Shneiderman's eight golden rules of interface design: For example, wherever possible, offer users options rather than ask them to remember information from one screen to another.

Shneiderman's eight golden rules of interface design: Reduce short-term memory load.

✓ How long is the menu to be?
✓ In what order will the items appear?
✓ What categories will be used to group menu items?
✓ How will division into groups be denoted, e.g., different colors, dividing lines?
✓ How many menus will there be?
✓ What terminology to use? (Results of requirements activities will indicate this)
✓ How will any physical constraints be accommodated, e.g., mobile phone?

Menu Design

✓ Good icon design is difficult
✓ Meaning of icons is cultural and context sensitive
✓ Some tips: always draw on existing traditions or standards, concrete objects or things are easier to represent than actions
✓ From clip art, what do these mean to you?

Icon Design

✓ moving around within and between screens
✓ how much interaction per screen?
✓ serial or workbench style?

Screen Design: How to split across screens

✓ white space: balance between enough information/interaction and clarity
✓ grouping items together: separation with boxes? lines? colors?

Screen Design: Individual screen design

✓ Relevant information available at all times
✓ Different types of information imply different kinds of display
✓ Consistency between paper display and screen data entry

Information display

1. help design the interface given a specification of the end users' tasks
2. help implement the interface given a specification of the design
3. create easy-to-use interfaces
4. allow the designer to rapidly investigate different designs
5. allow nonprogrammers to design and implement user interfaces
6. automatically evaluate the interface and propose improvements
7. allow the end user to customize the interface
8. provide portability
9. be easy to use

Tool Support