9. 8 Golden Rules of Interface Design Strive for consistency Reduce short-term memory load Support internal locus of control Permit easy reversal of actions Offer error prevention and simple error handling Design dialogues to yield closure Offer informative feedback Enable frequent users to use shortcuts 1 2 3 4 5 6 7 8 Interface design concepts
15. GIMP Image Editor Evolution Mail Client External Consistency Closing with unsaved data GThumb Image Viewer Interface design concepts
16. Microsoft Word Microsoft Excel Microsoft PowerPoint External Consistency Microsoft Office’s Ribbon Interface Why doesn’t everyone like it? Internal consistency? Interface design concepts
108. Usability incorporates the user, their environment, other tools and systems, workflow, and their goals/tasks. B.A. & Usability
109. Usability Our Definition The extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use. ISO 9241-11 B.A. & Usability
123. Beware of Colour Assumptions A ubiq uit ous logo Which letter(s) is/are red? Which letter(s) is/are green? Red/green deficit Blue/yellow deficit B.A. & Usability - Users
124. Pop Quiz Are there problems with these colours? B.A. & Usability - Users
130. Usability Our Definition The extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use. ISO 9241-11 B.A. & Usability
139. Usability Our Definition The extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficien cy and satisfaction in a specified context of use . ISO 9241-11 B.A. & Usability
183. Thank You & Questions OK/Cancel - “Cultural Sensibilities”
184.
Notes de l'éditeur
Motorola Razr http://my.opera.com/usability/blog/show.dml/169470 Meant to be used in conjunction with phone Forces same interface limitations on user If buttons were sufficient on phone, wouldn't need application phones are designed for calling ppl, not interacting with phone specifics Subtle and unexpected differences in buttons Different results when inputting via same interface Some buttons are nonfunctional (no consistency) Some new buttons Unnecessary display of phone interface (no benefits) Slide-out doesn't exist on phone, but provides most of the functionality Icons are difficult to understand Large amount of screen space wasted on non-functional interface Clippy http://xenon.stanford.edu/~lswartz/paperclip/paperclip.pdf Designed for basic users, but basic users don't use software to help them Often found to be intrusive, useless, and entertainment vs. useful
Links for fleshing out explanations http://www.ja-sig.org/wiki/display/UPC/Usability+Heuristics Professor Shneiderman’s rules were chosen: Applicability across mediums and technology His desire to include context in design Universal usability Conducted fundamental research in field of human-computer interaction http://en.wikipedia.org/wiki/Ben_Shneiderman
Internal consistency Screen layout from one screen to another operations behave the same way External consistency From one application to another Terminology used throughout product Prompts Menus Help screens Documentation Consistent text attributes throughout interface color , Layout Capitalization fonts
Screenshot by Brandon Walkin http://www.brandonwalkin.com/blog/2009/08/10/managing-ui-complexity/
http://www.actsofvolition.com/include/savealerts/screenshots.html (2005) Bad: Button icon variety Options are different Dialogue icon different Good Order of buttons
Increase the pace of interaction Abbreviations Special keys Hidden commands Macros
http://www.actsofvolition.com/include/savealerts/screenshots.html (2005) GThumb No cancel No title in window Unclear what the checkbox does – just this image or for ever?
Disallowing input will typically conflict with giving the user the locus of control, particularly expert users http://ethics.csc.ncsu.edu/risks/safety/killer_robot/killer_news5.html Opportunity to make your system look smart Data selection rather than typing Autocomplete Disallow alphabetic characters in numeric data fields Directive text associated with date entry fields E.g. Credit card: do not enter dashes Caps lock notice when typing in hidden field
UI Hall of Shame (oldie but a goodie) - http:// homepage.mac.com/bradster/iarchitect/shame.htm
http://ethics.csc.ncsu.edu/risks/safety/killer_robot/killer_news5.html Reduces anxiety of user, as they know anything can be undone if they make a mistake. Units of reversibility could be single action, data entry, or complete group of actions
Avoid tension and dissatisfaction: Surprising system actions e.g. stealing focus unexpectedly Tedious data entry Inability or difficulty in obtaining necessary information Inability to produce action desired
http://wiki.linuxquestions.org/wiki/Usability http://www.humanfactors.com/downloads/sep00.asp http://www.webword.com/moving/memory.html http://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_or_Minus_Two Human mind can typically recall 7 +/- 2 items in short term memory don’t design with this assumption (Miller’s “Magic 7” paper from 1956) recent research shows more like 2 to 4 “chunks” Focus of attention = short term memory Find the most important ideas and present those to the user Look for chunks of familiarity that leverage recognition not recall (familiarity and uniformity) (e.g. phone numbers prefix) Design to facilitate recognition rather than recall memory Begs the question – what will they recognize? Answer with mental models, metaphors Provide a means to drill down to further-nested ideas Visible options, dropdown menus, etc Take into account the ability to reduce memory load via proper training and practice
http://wiki.linuxquestions.org/wiki/Usability http://www.humanfactors.com/downloads/sep00.asp http://www.webword.com/moving/memory.html http://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_or_Minus_Two Human mind can typically recall 7 +/- 2 items in short term memory don’t design with this assumption (Miller’s “Magic 7” paper from 1956) recent research shows more like 2 to 4 “chunks” Focus of attention = short term memory Find the most important ideas and present those to the user Look for chunks of familiarity that leverage recognition not recall (familiarity and uniformity) (e.g. phone numbers prefix) Design to facilitate recognition rather than recall memory Begs the question – what will they recognize? Answer with mental models, metaphors Provide a means to drill down to further-nested ideas Visible options, dropdown menus, etc Take into account the ability to reduce memory load via proper training and practice
http://www.webword.com/moving/memory.html Bad: Pagination Splitting content across multiple pages Consider cross-page recall annoying, purpose is ad revenue does not work if have to recall info from other pages Makes printing difficult Makes finding/searching/scanning difficult Possibly dilutes SEO incoming links Avoid forcing users to memorize passwords Uses a chunk up Browsers can do this unless explicitly not allowed to by site (banks etc) Search engines shift recall to recognition Link colour (blue unvisited, purple visited) – population stereotype. Purple is a memory cue. Present list of available files rather than ask them to type in the filename. Auto completion. Gallery’s add items list of recently used folders?
No need to recall website addresses Suggestions provide for tangential or indirect recall If searching documents, no need to recall location or title
Consistency does not exist between icons, both in appearance, visual style, as well as in metaphors used Colour usage may come up – the colour is not relied upon to deliver the message though. Discussed later.
Jacob Nielsen - http://www.useit.com/alertbox/20030825.html Usability - Wikipedia - http://en.wikipedia.org/wiki/Usability Usability testing – Wikipedia - http://en.wikipedia.org/wiki/Usability_testing UCD – Wikipedia - http://en.wikipedia.org/wiki/User-centered_design
e) – UI Design – Wikipedia - http://en.wikipedia.org/wiki/User_interface_design
Golden Rules – how many broken? Consistency Shortcuts Informative feedback Yield closure Error prevention and handling Easy reversal of actions Internal locus of control Reduce short-term memory load Also involved: The application used to display it User’s expectation for how presentation slides work and are typically presented The setting large enough to see only one screen visible at a time The nature of the interactions between the “user” and the “system” 1 slide on a screen at a time Requiring people to remember items without giving them time to memorize or advance notice The number of items was too large to remember them, and they weren't clearly different
Red/Green Blue/yellow Monochromacy Colour blindness Inability to differentiate specific colours Genetic basis Design impact: Do not rely on colour coding alone Maybe the world is gray Motion blindness Perception of motion as a series of frames instead of fluid motion Not genetic, caused by brain injury Design impact: Motion is a very powerful visual attractant Do not assume full motion is visible Note: slow computers can result in a similar effect
The colours here are not imperative to using Google The point though is that colour should not be solely relied upon as it is not a constant across all users, particularly in emergent situations. Deuteranope (red/green deficit) Tritanope (blue/yellow deficit)
The colour is not relied upon to deliver the message. Therefore is can be considered supplementary to the message. So essential question is about design choices.
What do they need or want to do? How much training is needed? Can users easily accomplish their tasks Can users recover from errors or does someone die? What and how many errors do users make when interacting with the product or product to be replaced/improved?
http://www.defibtech.com/products/index.html
What is the user's context? Supporting materials available What has to be left to the machine Interactions with other systems Criticality of use How important is it to have it work right the first time? All the time? Physical influences Portability Temperatures Environment
Small Arms for the 1980s – intended to be standard issue for British Armed Forces Gun designed without field tests and consideration for how and where it would be used Gun design began in 1960s, prototypes trialed in mid 70’s, production completed in 1994. Over 30 years in development and over 470 million pounds spent on design alone. Quiz: what do these people all have in common? Stationary – ammunition clip typically caught on clothing and fell out while soldier was running (e.g. during testing the full ammunition clip was only inserted once gun was at firing range) Shooting from right side of body – hot clips firing out one side of the gun made it impossible to shoot from the left shoulder Other issues: Plastic would swell in rain, jamming safety switch on/off Lubrication did not work in sandy conditions, causing jams Went off when dropped Safety catch broke when trigger pulled hard Sent back for redesign – rifles must be dependable and safe