1. how can weimprove the usabilityof a design? 1lecture 03 | 219 digital concepts | structurejoe natoli | givegoodux.com

2. 80/20 rulejoe natoli | givegoodux.com

3. 80/20 rule 3 80% of a products usage involves 20% of its features 80% of a towns trafc is on 20% of its roads 80% of progress comes from 20% of the effort 80% of errors are caused by 20% of the componentsjoe natoli | givegoodux.com

4. 80/20 rule 4 3 all elements in a design are not equal use the 80/20 rule to assess the value of elements, target areas of redesign and optimization, and focus resources if the critical 20% of a products features are used 80 percent of the time, design should focus primarily on those features non-critical functions that are part of the less-important 80% should be minimized or removed altogether from the designjoe natoli | givegoodux.com

5. accessibilityjoe natoli | givegoodux.com

6. accessibility 6 3 things should be designed to be usable by as many people as possible often focused on helping people with disabilities increasingly clear that many required accommodations can be designed to benet everyone also known as barrier-free design and related to universal design and inclusive designjoe natoli | givegoodux.com

7. accessibility 7 3 perceptibility means everyone can perceive the design, regardless of sensory abilities operability means everyone can use the design, regardless of physical abilities simplicity means everyone can easily understand and use the design, regardless of experience, literacy, or concentration level forgiveness means designs minimize the occurrence and consequences of errorsjoe natoli | givegoodux.com

8. aesthetic-usability effectjoe natoli | givegoodux.com

9. aesthetic-usability 9 aesthetic designs are perceived as easier to use than less-aesthetic designs its common for people to name and develop feelings toward designs that have fostered positive attitudes (e.g., naming a car) personal, positive relationships with a design evoke affection, loyalty, and patienceall signicant factors in long-term success these positive relationships also make people much more tolerant of errorsjoe natoli | givegoodux.com

10. conrmationjoe natoli | givegoodux.com

11. conrmation 11 veries that an action or input is intentional and correct before its performed conrmations slow task performance reserve for use with critical or irreversible operations only allow less critical conrmations to be disabled after an initial conrmationjoe natoli | givegoodux.com

12. constraintsjoe natoli | givegoodux.com

13. constraints 13 constraints limit possible actions for example, hiding unavailable software controls constrains the options that can be selected simplies usability and minimizes error can reduce the sensitivity of controls minimizes unintentional inputs prevents or slows dangerous actionsjoe natoli | givegoodux.com

14. physical constraints 14 paths convert applied forces into linear or curvilinear motion using channels or grooves (e.g. scroll bar in user interfaces) axes convert applied forces into rotary motion, providing a control surface of innite length in a small space (e.g. a trackpad) barriers absorb or deect applied forces stopping, slowing, or redirecting forces around the barrier (e.g. boundaries of a mobile phone screen)joe natoli | givegoodux.com

15. psychological constraints 15 symbols inuence behavior by communicating meaning through visuals and/or language (e.g. text & icon of a warning sign) conventions inuence behavior based on learned traditions, practices and mental models (e.g. red means stop, green means go) mappings inuence behavior based on perceived relationships between elements (e.g. light switch position)joe natoli | givegoodux.com

16. controljoe natoli | givegoodux.com

17. control 17 level of control provided by a design should be related to the prociency and experience levels of the people using it beginners do best with reduced amount of control experts do best with greater amount of control interactive design can accommodate these varying needs by offering multiple ways to perform a taskjoe natoli | givegoodux.com

18. cost - benetjoe natoli | givegoodux.com

19. cost-benet 19 an activity will be pursued only if its benets are equal to or greater than the costs determines design quality from a user perspective: if costs associated with interaction outweigh the benets, the design is poor if the benets outweigh the costs, the design is goodjoe natoli | givegoodux.com

20. cost-benet 20 how much reading is too much to get the point of a message? how many steps are too many to set the time and date on your camera? how long is too long for a person to wait for a web page to download? it depends on the benets of the interaction design features or elements that excite designers are often never used or even noticed by peoplejoe natoli | givegoodux.com

21. entry pointjoe natoli | givegoodux.com

22. entry point 22 we do judge books by their covers, apps or sites by their rst pages ever click on a URL only to see a splash screen,followed by several pop-up windows with ads, followed by a slow-loading page? all just to enter a site that didnt have the information you were looking for? these errors in entry point design annoy visitors who make it through, or deter visitors altogetherjoe natoli | givegoodux.com

23. errorsjoe natoli | givegoodux.com

24. errors 24 two kinds of errors: slips are the result of automatic, unconscious processes, and frequently result from a change of routine or an interruption of an action. (e.g. you forget your place in a procedure when interrupted by a phone call) minimize by providing clear feedback: consequences and corrective actions position controls to prevent accidental activation of functions that may have detrimental consequencesjoe natoli | givegoodux.com

25. errors 25 mistakes are conscious, sometimes referred to as errors of intention or errors of planning, and occur when an intention is inappropriate. (e.g. nurse interprets an alarm incorrectly and then administers the wrong medicine) minimize by increasing situational awareness and reducing noise make key indicators and controls visible within one eyespan when possible provide just enough feedback to accomplish warnings and other functions, but no more.joe natoli | givegoodux.com

26. iconic representationjoe natoli | givegoodux.com

27. iconic representation 27 similar iconic images that are visually analogous to an action, object, or concept most effective at representing simple actions, objects, or concepts, and less effective when the complexity increasesjoe natoli | givegoodux.com

28. iconic representation 28 example images of things that exemplify or are commonly associated with an action, object, or concept particularly effective at representing complex actions, objects, or conceptsjoe natoli | givegoodux.com

29. iconic representation 29 symbolic iconic images that represent an action, object, or concept at a higher level of abstraction effective when actions, objects, or concepts involve well-established and easily recognizable objectsjoe natoli | givegoodux.com

30. iconic representation 30 arbitrary iconic images that bear little or no relationship to the action, object, or conceptthe relationship has to be learned should only be used when developing cross-cultural or industry standards that will be used for long periods of time this gives people sufcient exposure to an icon to make it an effective communication devicejoe natoli | givegoodux.com

31. performance loadjoe natoli | givegoodux.com

32. performance load 32 degree of mental and physical activity required to achieve a goal if the performance load is high, performance time and errors increase, and the probability of successful accomplishment decreases if the performance load is low, performance time and errors decrease, and the probability of successful accomplishment increases two types of performance loads: cognitive and kinematicjoe natoli | givegoodux.com

33. performance load 33 cognitive load amount of mental activityperception, memory, problem solvingrequired to accomplish a goal e.g. remembering commands vs. graphical UI strategies for reducing cognitive load: minimizing visual noise chunking information using memory aids automating computation- and/or memory-intensive tasks.joe natoli | givegoodux.com

34. performance load 34 kinematic load degree of physical activitynumber of steps or movements, or amount of forcerequired to accomplish a goal e.g. the telegraph communicated letters one at a time through a series of taps on a mechanical armature. strategies for reducing kinematic load: reducing steps required to complete tasks minimizing range of motion and travel distances automating repetitive tasksjoe natoli | givegoodux.com

35. personasjoe natoli | givegoodux.com

36. personas 36 its better to perfectly meet the needs of the critical few than to poorly meet the needs of many personas involve the creation of proles for a small number of archetypal users, each prole representing a composite of a subpopulation of users information for the proles comes from user and stakeholder interviews, reviews of market research and customer feedback, and statistics on product usejoe natoli | givegoodux.com

37. recognition over recalljoe natoli | givegoodux.com

38. recognition over recall 38 people are better at recognizing things theyve previously experienced than recalling those things from memory recognition tasks provide cues that facilitate searching through memory e.g. multiple-choice vs. short-answer question recognition memory is built through exposure its something that has been experienced before e.g. sight, sound, smell, touch minimize the need to recall information from memory whenever possiblejoe natoli | givegoodux.com

39. wayndingjoe natoli | givegoodux.com

40. waynding 40 whether navigating a college campus, the wilds of a forest, or a website, waynding involves the same four stages: orientation route decision route monitoring destination recognitionjoe natoli | givegoodux.com

41. waynding 41 successful waynding in UI design answers the following user questions: where am I? how did I get here? where else can I go? how will I know when Im there?joe natoli | givegoodux.com

42. assignment For next weeks class, rene your interface concept based on the feedback and suggestions you received in critique last week. How can you improve what you have now? We will have a critique at the beginning of class next week.joe natoli | givegoodux.com