VCE IT Theory Slideshows by Mark Kelly 2016-2019 study design By Mark Kelly, vceit.com,...

VCE IT Theory Slideshows by Mark Kelly2016-2019 study design

By Mark Kelly, vceit.com, mark@vceit.com

Design Principles

The Glossary (sort of) says

Design principles are accepted characteristics that contribute to the

– functionality and – appearance

of solutions.

• Principles related to functionality are 1. Useability including

a) robustness, b) flexibilityc) ease of use

2. Accessibility including a) navigationb) error tolerance

• Principles related to appearance are1. alignment, 2. repetition, 3. contrast, 4. space5. balance.

Functionality Design Principles

1. Useability including a) robustness, b) flexibilityc) ease of use

Functionality Design Principles> Usability

> Robustness

• The ability of a computer system to cope with errors during execution.

• The ability of a solution to continue operating despite abnormalities in data inputs, calculations

• Making a product insensitive to variations it may encounter.

Resists failing in the face of:- Invalid data (by using

comprehensive data validation)

> Robustness

Resists failing in the face of becoming overloaded • by queuing incoming work• by being scalable• by using high-capacity

components• by using redundant equipment

(e.g. standby cooling fans)

> Robustness

Resists failing in the face of runtime errors • by testing the amount of free

memory before allocating it;• by checking free disk space

before saving; • by checking printer/network

availability before relying on them

> Robustness

Resists failing in the face of user error (see error tolerance later)- by anticipating common errors

and gracefully handling them- by checking for input error (e.g. a

browser may quietly ignore malformed HTML)

> Robustness

Use reliable components, such as trustworthy, secure, up-to-date • device drivers• plugins, • algorithmse.g. using a media player that can cope with nearly any media, even rare formats or media with errors.

> Robustness

Anticipates future requirements• A value that is now always integer may at

some stage need decimal places (e.g. GST rate)

• A small value may one day outgrow a confining data type (e.g. using the small byte data type won’t cope if the value rises above 255.)

> Robustness

Anticipates future requirements• Enforcing a 4-digit postcode will fail if

you later get US customers.• Using 2-digit years before 2000.

> Robustness

Anticipates and allows uncommon conditions, e.g.• Don’t forbid spaces in family names

(fails for von Zeppelin, de Kretser)• A street name without a street type

(e.g. “11 Broadway”)

> Robustness

Can be helped with thorough and imaginative testing.• But can be costly in terms of time

and effort during design, development & testing.

Functionality Design Principles> Usability> Flexibility

Flexibility – the ability of a solution to adapt to new or changed conditions or requirements.

Flexibility – a solution that can be used for more than one purpose.

• e.g. a tablet that converts into a laptop computer

• a user manual that also contains tutorials.

• a router box that includes a WAP, print server, ADSL modem, switch.

e.g. a WAP that copes with A,B,G,N, AC wireless protocols.e.g. email software that handles IMAP and POP.e.g. word processor that can import a variety of text from other formats, products or previous versions.

e.g. USB 3.0 ports that are backwardly-compatible with USB 1.0, 2.0 products.e.g. an OS like MS Windows 10 that can still run programs from decades earlier.

Achieving flexible solutions…• Don’t build in constants (e.g. 10% GST)

that cannot later be changed. Use an .ini file or registry to store settings.

• Let users customise their settings, shortcuts, preferences, menus, themes, layouts

• Avoid making restrictive assumptions (e.g. all users will have mice & large monitors)

Flexible solutions…• Can deal with a variety of related

requirements, e.g. • software that can burn CD,

DVD, Blu-Ray in +R, -R, +RW, -RW formats and also disk images (ISO)

Flexible solutions…• Cater for a variety of users – e.g.

command entry using menus, keyboard shortcuts, buttons, toolbars.

• Can be configured for regional differences, e.g. language, spell-check dictionaries, date formats, currencies.

E.g. multimodal solution that lets users choose to have either

• full control over the sequence and speed of information, or

• an automatic presentation.

Browser software that can• Display webpages• Open PDF files• Play music and video• Play games and run apps• Read eBooks• Narrate text aloud• Access email• Act as personal assistants• Scan for viruses

Warning – flexibility comes at a cost. Common downsides of flexibility:- It does many jobs, but all of them are done

at a basic level of - It will take more time and effort to develop- It will be expensive to buy, or it will be BIG.- Its irrelevant functionality (‘bloat’) may

annoy users or make essential functions harder to perform.

Software bloat…

http://www.27months.com/2009/03/the-virtues-of-small-software/

> Ease of use

Ease of use is important for • Beginners, children• Occasional users• People with special needs

(see ‘Accessibility’)

> Ease of use

Use task automation• Wizards• Macros• ‘Express settings’• Beginner / Expert

> Ease of use

Affordance – where an interface leads users to naturally take correct steps.

Creates an “intuitive” interface requiring little training.

> Ease of use

Affordance e.g. a 3D button that looks like it should be clicked with the mouse.

> Ease of use

Affordance• e.g. Red text that

automatically suggests danger or urgency.

• Icons that need few language skills to interpret

> Ease of use

Affordance - A display that shakes when incorrect data is entered, as if shaking its head.

> Ease of use

Is helped by…• Context-sensitive help• Online documentation• Tool tips• Onscreen instructions

> Ease of use

Is helped by…• Onscreen

instructions

2. Accessibility including a) navigationb) error tolerance

Above: poor navigation and poor error tolerance

Accessibility

In VCE IT relates to catering for people with disabilities or special needs.

Disabilities or special needs.e.g. • Poor vision• Poor coordination, tremors• Weak language skills• Missing or non-functional limbs• Intellectual disability• Extreme youth or age• Lack of tech knowledge

Colour Blindness

Accessibility

It does not refer to information being easy to find, or quick to download.

Functionality Design Principles> Accessibility> Navigation

Give users a choice of how to navigate e.g.• Shortcut keys• Menu bars/ribbons• Drop-down menus• Buttons• Voice input• Screen taps

• Make navigation controls easy to find, e.g. top or side of screen

• Make nav work regardless of screen size or input method

• Make navigation controls big enough to easily read and click

• Minimise clicks/typing required (e.g. open a menu on mouse-over rather than a click)

Functionality Design Principles> Accessibility

> Error Tolerance

Error tolerance• Anticipating and coping with

user errors

> Error Tolerance

Common errors• Clicking the wrong button• Entering invalid data• Not entering mandatory data• Selecting unavailable options

> Error Tolerance

Error Tolerant handling

Clicking the wrong button

Always offer a ‘Back’ or ‘Cancel’ link. Confirm serious actions (‘Are you sure you want to…’)

Entering invalid data Range or type validation. Give on-screen tips about data formats and types.Use appropriate GUI data entry controls

Not entering mandatory data

Existence validation. Clearly mark fields that are required.

Selecting unavailable options

Don’t offer options that make no sense. Grey out unavailable options.Disable buttons that are currently unacceptable.

> Error Tolerance

Error Tolerant handling

Accidental data loss

Provide multiple-undo; delete to a recoverable bin; background saving of documents.

Typing errors Spell checking; auto-correction (e.g. “Did you mean…?”, or quietly adding a missing Http:// to a URL)

Lack of skill Anticipatory advice (e.g. “This will take some time. Do you want to continue?”)Diagnostic information (“You can’t edit this layer because it is locked. Unlock it in the ‘Edit’ menu.”)Tool tips, context-sensitive help.

Accidental mouse click

Trigger event on mouse-up event, not mouse-down. User can slide mouse pointer off the button and not trigger the event.

Appearance Design Principles> Alignment

Alignment – the lining-up of objects to group or organise them– horizontal– vertical– diagonal– left / right edge, centred

Diagonal alignmentCreates a feeling of imbalance, movement, action.

Centred vertically

Centred horizontally

Vertical menu

Horizontal menu

Text – left-justified (ragged right edge)Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Text – centred (only for headings!)Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim

ad minim veniam.

Text – right-justified (rarely used)Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim

ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in

culpa qui officia deserunt mollit anim id est laborum.

Text – fully-justified (straight edges)Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Text – right-justified (rarely used, but can be effective when wisely-chosen)

Powerpoint automatically shows alignment (with dotted red lines) as objects are moved around.

Appearance Design Principles> Repetition

The repeated use of visual elements creates a sense of unity, predictability and consistency. Lets users extract information quickly.

e.g. – All main headings are 24 point, bold, sans

serif. – All links are underlined. – An icon always means the same thing on all

pages.– The same colour scheme is used throughout– Menus always appear in the same place on

every page56

And a sudden change to a repeated element will draw attention to it more dramatically.e.g. suddenly making some text bold or coloured so it stands out from the usual text.

Appearance Design Principles> Contrast

ContrastThe difference between foreground and background colours. Greatly affects readability.

Appearance Design Principles> Space

Space – refers to the distance around or between visual elements. There is positive and negative space.

• Positive space represents the object.

• Negative space surrounds the object.

• If you see a vase, the white is positive space.

• If you see faces, the black is the positive space.

• Creative use of positive and negative space can lead to dramatic and eye-catching results

Space may also include (non-examinable) the concept of proximity• Items that are close to each other are more likely to

be related or connected.• Items that are visually separated are visually

differentiated (like paragraphs of text with space between them)

Clever use of space can• establish contrast, emphasis and hierarchy;• generate drama and tension;• provide visual rest between groups of elements;

• make an item stand out as being separate or different

Space also is important in helping legibility and readability. Which of these would you rather read?

Poor spacing Good spaceLorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean volutpat enim id nulla molestie, et vulputate dui venenatis. Curabitur egestas elit ullamcorper nisl laoreet posuere. Integer condimentum dolor arcu, in tincidunt mi molestie a. In hac habitasse platea dictumst. Vivamus luctus, elit vitae molestie laoreet, risus turpis auctor eros, a posuere elit urna eget tellus. Vivamus a efficitur mi, ac viverra lorem. Ut viverra purus eget leo tempor imperdiet. Suspendisse ac orci lorem. Interdum et malesuada fames ac ante ipsum primis in faucibus. Morbi ac pharetra felis. Nulla eu ullamcorper ligula, ac laoreet dui. Etiam bibendum, lectus nec consectetur condimentum, orci nibh convallis lectus, non bibendum velit mi at purus. Aliquam vulputate placerat interdum. Maecenas condimentum felis a lacus ultricies, vitae eleifend nisl luctus. Fusce semper mauris aliquam nibh elementum tristique. Nam nec laoreet purus.

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean volutpat enim id nulla molestie, et vulputate dui venenatis. Curabitur egestas elit ullamcorper nisl laoreet posuere. Integer condimentum dolor arcu, in tincidunt mi molestie a.

In hac habitasse platea dictumst. Vivamus luctus, elit vitae molestie laoreet, risus turpis auctor eros, a posuere elit urna eget tellus. Vivamus a efficitur mi, ac viverra lorem. Ut viverra purus eget leo tempor imperdiet. Suspendisse ac orci lorem. Interdum et malesuada fames ac ante ipsum primis in faucibus. Morbi ac pharetra felis. Nulla eu ullamcorper ligula, ac laoreet dui.

Etiam bibendum, lectus nec consectetur condimentum, orci nibh convallis lectus, non bibendum velit mi at purus. Aliquam vulputate placerat interdum. Maecenas condimentum felis a lacus ultricies, vitae eleifend nisl luctus. Fusce semper mauris aliquam nibh elementum tristique. Nam nec laoreet purus.

The use of space also conveys qualities of • Maturity• Elegance• Sophistication, • Quality • Simplicity • Luxury• Confidence• Honesty

Before Google, search engine front pages looked like this……

Then Google came…

The moral… don’t crowd pages and cram in as much text as possible.

Use multiple pages or screens.

Provide• Generous left/right/top/bottom page margins• Space between paragraphs• Space between text and images• Space between headings and body text• Readable line spacing between lines of body text• Otherwise you’ll end up with something like this…

Appearance Design Principles > SpaceProvideGenerous left/right/top/bottom page marginsSpace between paragraphsSpace between text and imagesSpace between headings and body textReadable line spacing between lines of body text

Appearance Design Principles > Space

Use the space provided.A phone display, for example is usually tall and narrow when the phone is held normally.Align labels and text fields vertically to make best use of the space.

Appearance Design Principles> Balance

Balance.Objects are distributed evenly to create a satisfying balance.

The penguin dominates the left of the image, so the text is right-justified to balance it on the right.

Balance.Objects are distributed evenly to create a satisfying balance.

The text and image do not interfere with each other, and efficiently use all of the slide’s area.

Appearance Design Principles> BalanceBad Balance.Objects are distributed unevenly to create a unsatisfying balance.

Top slide lacks design. Alignment is random. Balance is wonky.Space is poorly distributed.

Bottom slide has symmetry. Related items are visually together (i.e. good proximity). Contrast focuses attention on main info.

Mark Kellymark@vceit.com

vceit.comThese slideshows may be freely used, modified or distributed by teachers and students anywhere

butthey may NOT be sold.

they must NOT be redistributed if you modify them.

This is not a VCAA publication and does not speak for VCAA.Portions (e.g. exam questions, study design extracts, glossary terms) may be copyright Victorian Curriculum and

Assessment Authority and are used with permission for educational purposes. Thanks, guys!

VCE IT THEORY SLIDESHOWS2016-2019 study design

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