Ergonomics

1. Ergonomics

2. Contents • Arrangement of controls • Health issues • Use of color

3. Ergonomics • Ergonomics, or human factors, is the study of the layout of controls and the physical environment • The goal is to increase user performance by improving the control layout and the environment • This is a well-established field and we will look only at the parts pertinent to computing

4. Arrangement of Controls • Sets of controls should be group logically to allow rapid access by the user • This is not as critical when using a spreadsheet as when using industrial controls, but it does contribute to productivity • Poorly placed controls can lead to • Inefficiency • Errors • Frustration

5. Arrangement of Controls • Example • One online news reader placed the key to read articles beside the key to unsubscribe from the news group • As a result, a slip of the finger would unsubscribe rather than reading news • This led to the inadvertent removal of news groups • The operation could be reversed, but at a cost of lost time

6. Arrangement of Controls • It is important to group controls together logically • The rationale for control grouping depends on the nature of the application • We will now look at various ways you might group controls

7. Control Groupings • Functional • Controls that perform similar functions are grouped together • Sequential • Controls are laid out so that buttons used to perform common sequences are arranged one after another • Frequency • Controls are organized according to how frequently they are used

8. Example Groupings * Indigo.ca

9. Example Groupings • Note • Shipping information is beside billing • Payment information is all together • Itemized list of order is all in one place • List has totals similar to a paper form that users would be familiar with • A list of communications about the order is shown at the bottom • Decorative dividers are used to partition the space to make it easier to find the parts

10. Alignment • How lists are aligned can make a major difference in how easy they are to read • Which list is easier to read? 34.23 2096.00 598.34 65290.50 17.47 34.23 2096.00 598.34 65290.50 17.47

11. Alignment • Which is the easiest way to find a surname in the following lists? Wile Coyote Donald Duck Fred Flintstone Pepe Gonzales Barney Rubble Betty Rubble Wile Coyote Donald Duck Fred Flintstone Pepe Gonzales Barney Rubble Betty Rubble Coyote, Wile Duck, Donald Flintstone, Fred Gonzales, Pepe Rubble, Barney Rubble, Betty

12. Alignment • Different ways of handling multi-column lists. • The difficulty in (i) is being able to follow the rows across • Each of the other approaches tries to correct this problem * Dix, et al

13. White Space • Typographers, artists, and photographers all know that the negative space surrounding an image can be as important as the image • It ca visually separate • It can imply shapes • It can make it easier to read and find things • It can draw attention to parts of the page

14. White Space * Dix, et al

15. Data Entry Forms • There are many forms displayed which require the user to enter information • Often, the fields are of different sizes and do not line up • It is best to • Align input fields • Right justify label fields • Arrange fields logically • Allow data to be entered left-to-right, top-to-bottom

16. UI Standards • Adopting common standards for user interfaces will • Create users who recognize buttons, sliders, and input fields • Create a common look and feel that is easy to recognize • Use controls that everyone knows how to operate • Use single and double clicks consistently

17. User’s Position • Not only must the controls be laid out logically, they must be easy for the user to reach and manipulate • The user must • Be able to reach all controls without excessive body movement • Be able to reach controls regardless of the height of the user • Critical displays should be at eye level • Lighting should not cause glare or reflection • Controls are spaced to allow adequate room for the user to manoeuvre

18. Health Issues • We do not normally think of computers as dangerous, but there are many situations in which health concerns arise • Physical position • Users work for long periods of time • Placement of controls which requires them to be in uncomfortable positions will result in muscle strains, back problems, headaches, etc.

19. Health Issues • Temperature • Performance deteriorates when temperatures are significantly outside the norm • Working environments should be temperature controlled so that they are comfortable

20. Health Issues • Lighting • Adequate lighting should be provided so that users can see computer screens without trouble • Computer screens should be oriented to minimize reflections from windows or having the screen washed out by daylight

21. Health Issues • Fluorescent lights are bad, incandescent are better and indirect natural light is the best • Use hoods and drapes to reduce glare

22. Health Issues • Noise • Excessive noise can be a health hazard • Computer equipment should produce a low level of noise • Sound should be used judiciously in the user interface as it can be more distracting than helpful

23. Health Issues • Time • The time spent using computers should be controlled • Too much time can result in • Repetitive strain injuries • Fatigue • Overexposure to harmful emissions from CRTs

24. Health Issues • Chairs • Select the one that is the most comfortable for you • Change the height and tilt until it is as comfortable as possible

25. Health Issues • Keyboards • Adjust the height so that there is minimal bending of the wrist • Arms should hang loose to avoid the shoulders cramping • The forearms should have some support

26. Health Issues • Mouse • Hold it lightly, not with white knuckles • Use your whole arm & shoulder to move the mouse, not just the wrist • Avoid maintaining the same position for prolonged periods

27. Health Issues • Human issues • Assume a posture which is comfortable but which does not have to be rigidly straight • Loosen you muscles, stretch, and roll your neck even before you start to work • Take breaks at least once an hour to get up and move around

28. Health Issues * Dan Mcleod

29. Health Issues * Dan Mcleod

30. Health Issues * Dan Mcleod

31. Health Issues * Dan Mcleod

32. Health Issues * Dan Mcleod

33. The Use of Color • Colors used should have sufficient contrast to be discernable • Blue should not be used for the display of critical information • If color is used as a cue, then some other cue must be used as well so that the interface can be used by color blind

34. The Use of Color • To test the usability of a color interface, turn the saturation down to the point where it is monochrome. Is the interface still usable? • Colors should conform to user expectations • Red – stop • Green – go • Yellow – hold or caution • Keep in mind that the meaning of colors differs among cultures and might have to be localized

35. The Use of Color • Color should be used sparingly • Overuse can make the interface distracting or confusing • Poor selection of colors can make some users unhappy • Interfaces which look like circuses are not good interfaces

36. Accessibility • Accessibility provides aids for users who suffer from some type of disability • Disabilities addressed include • Vision impairment • Hearing impairment • Lack of mobility which would affect typing or use of mouse

37. Accessibility • Microsoft Windows provides several tools to aid users • A narrator which reads text off the screen, announces the active window when it changes, and can read text as it is typed • An on-screen keyboard which allows typing with the mouse • A magnifying glass to show a portion of the screen enlarged • The ability to change font sizes to make it easier to read

38. Magnifier

39. On-Screen Keyboard