1. July 2, 2007Mohamad Eid Facets of Interaction: Text Chapter 13

2. July 2, 2007Mohamad Eid Can you read this? I cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. The phaonmneal pweor of the hmuan mnid! Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Amzanig huh? Yaeh, and I awlyas thought slpeling was ipmorantt.

3. July 2, 2007Mohamad Eid Outline Human Issues Concerning Text Using Text in Interaction Design Technical Issues Concerning Text

4. July 2, 2007Mohamad Eid Human Issues Concerning Text The Reading Process The Reading Purpose Paper versus Screens

5. July 2, 2007Mohamad Eid Human Issues Concerning Text The Reading Process Saccades: Quick, jerky movements Fixations: Intermittent pauses on areas of interest Visual and cognitive processing occurs during fixation but not during saccades. If text is difficult to comprehend, if it includes long or unfamiliar words, fixations increase in duration

6. July 2, 2007Mohamad Eid Human Issues Concerning Text The Reading Process Experienced readers recognize word shapes

7. July 2, 2007Mohamad Eid Human Issues Concerning Text The Reading Process We read extended text passages more quickly in lowercase than uppercase Lowercase presentation is more common Lowercase words have more distinctive shapes

8. July 2, 2007Mohamad Eid Human Issues Concerning Text The Reading Purpose Continuous process (novel) Scanning Reading from screens or paper

9. July 2, 2007Mohamad Eid Human Issues Concerning Text Paper versus Screens Paper is more flexible than electronic media We often rely on our spatial memory when we search for information Place holders

10. July 2, 2007Mohamad Eid Paper versus Screens The ability to annotate aids comprehension Human Issues Concerning Text

11. July 2, 2007Mohamad Eid Using Text in Interaction Design Commentary/Instrumental Legibility Readability Physical Factors

12. July 2, 2007Mohamad Eid Using Text in Interaction Design Commentary – Text that informs The most common form is help text Contextual help provides immediate assistance to users without requiring them to leave the context in which they are working, such as pop-up menus. Procedural help provides the steps necessary for carrying out a task. Reference help serves as an online reference book. Conceptual help provides background information, feature overviews, or processes.

13. July 2, 2007Mohamad Eid Using Text in Interaction Design Instrumental – Text that does work (Ramey, 1989) Controls: the control’s function and its label are viewed as one entity Buttons Checkboxes Radio Buttons Icons Hyperlinks

14. July 2, 2007Mohamad Eid Using Text in Interaction Design Hypertext Hypertext links must give unambiguous indications of the target destination Krug - Don’t Make Me Think (2006) - suggests that what is important is not so much the number of links that a visitor must click but rather the quality of the links

15. July 2, 2007Mohamad Eid Using Text in Interaction Design Legibility Legibility is an essential first step in the reading process We must take these environmental conditions into consideration when we are making determinations about font size and foreground/background contrast. Design for the least favorable conditions

16. July 2, 2007Mohamad Eid Using Text in Interaction Design Legibility We must also consider age and possible vision impairments Our capacity to perceive details decreases with age

17. July 2, 2007Mohamad Eid Using Text in Interaction Design Readability Comprehension is affected by: Line length Line spacing Formatting Margin width Scrolling It is also affected by grammatical issues, such as semantics and syntax

18. July 2, 2007Mohamad Eid Using Text in Interaction Design Readability Use the terms people will see in the interface Technical terminology should be avoided Word-for-word translations can create confusion Italian street signs

19. July 2, 2007Mohamad Eid Using Text in Interaction Design Readability – Ambiguous text Avoid noun stacks; they are ambiguous Linguistic “Escher effects” (Ramey,1989) Input Mode Search Results

20. July 2, 2007Mohamad Eid Using Text in Interaction Design Physical Factors Font size Line length Margin width Vertical line spacing Alignment Contrast Scrolling versus paging

21. July 2, 2007Mohamad Eid Using Text in Interaction Design Font size Factors that affect font size: (Horton, 1994) Reading Distance—Greater distances require larger text. Screen Resolution—Smaller text requires greater resolution to keep the characters clear and legible. Text/Background Contrast—Negative contrast is optimal (black type on a white background). Visual Acuity of User—Not all users have 20/20 vision. Type of Reading—Text can be scanned, read word by word, or read character by character

22. July 2, 2007Mohamad Eid Using Text in Interaction Design Font size General benchmark formula for font size, given normal vision and optimal conditions Font Size = 2d(tan(θ/2)) X DPI

23. July 2, 2007Mohamad Eid Using Text in Interaction Design Line length Line length affects reading performance but not comprehension Lines of greater length are read more quickly People prefer medium line lengths

24. July 2, 2007Mohamad Eid Using Text in Interaction Design Margin width Shorter lines—4 inches—with large margins increased reading performance (Youngman and Sharff, 1998) Maximal use of white space

25. July 2, 2007Mohamad Eid Using Text in Interaction Design Vertical line spacing The spacing between lines of text (single spacing, double spacing, etc.) is called leading Double spacing has been shown to improve reading speed (Kolers, Duchnicky, & Ferguson, 1981) It might necessitate a smaller font size to increase the amount of visible information per screen

26. July 2, 2007Mohamad Eid Using Text in Interaction Design Alignment For optimal reading of lengthy texts, right and center alignments should be avoided Text should also be considered a graphical component of a page

27. July 2, 2007Mohamad Eid Using Text in Interaction Design Contrast Contrast sensitivity decreases significantly with age

28. July 2, 2007Mohamad Eid Using Text in Interaction Design Color Contrast Because black and white have the highest contrast the addition of any color will reduce the contrast Luminance contrast is more significant than color contrast

29. July 2, 2007Mohamad Eid Using Text in Interaction Design Scrolling versus paging Consistent link location. Paging Scrolling

30. July 2, 2007Mohamad Eid Using Text in Interaction Design Scrolling versus paging Scrolling facilitates maintenance and printing The choice of paging versus scrolling depends on task and layout

31. July 2, 2007Mohamad Eid متشکرم 谢谢 ありがとう