1. Man and Machine: Introduction to HCI (MMI)

2. Contents HCI: Introduction Design Rules: – Guidelines – Principles – Theories 2

3. What is HCI ? Human–computer interaction (HCI) or Man-Machine Interaction (MMI) is the study of interaction between people (users) and computers. 3

4. HCI Human-computer interaction (HCI) is: “concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them” (ACM SIGCHI, 1992, p.6) 4

5. Goal of HCI Is to enhance the interaction between humans and computer systems 5

6. Usability = Quality Errors Satisfaction Learnability Efficiency Memorability Usability 6

7. Good UIs on Successful Products Palm succeeded where other handhelds had failed due to a focus on usability Apple iPod / Apple iPhone Apple iPad Wii controller, vs. XBox, PS3 graphics & power 7

8. Bad UIs can Sink Products & Companies Ford dropped in ratings due to touch screen interface – “Despite Ford’s improvements in manufacturing quality, their overall ratings fell precipitously this year due solely to the poor software interaction on their dashboards.” – NYT, Cooper ReportNYTCooper Report – “’annoying’ behavior of their driver-facing interactive systems that caused their ratings to plummet.” Brad Myers (Human Computer Institute) 8

9. Bad UIs Can Cause Disasters Aegis – July 4, 1988; Iranian Airbus shootdown by the Vincennes http://www.washingtonpost.com/wp-srv/inatl/longterm/flight801/stories/july88crash.htm http://en.wikipedia.org/wiki/USS_Vincennes_%28CG-49%29 Deaths in kids: http://pediatrics.aappublications.org/cgi/content/abstract/116/6/1506 http://pediatrics.aappublications.org/cgi/content/abstract/116/6/1506 – “Unexpected Increased Mortality After Implementation of a Commercially Sold Computerized Physician Order Entry (CPOE) System” Because it took so much longer, did not reduce errors overall Florida ballots (2000) http://www.asktog.com/columns/042ButterflyBallot.html 9

10. Florida Ballots in 2000 10

11. A measure of usability …. Return on investment in the range of 3:1 to 100:1 11

12. Design Rules: Guidelines, Principles & Theories

13. Design Rules Design rules are rules a designer can follow in order to increase the usability of the eventual software product. These rules can be classified based on authority and generality where: – Authority: whether rule must be followed or is merely a suggestion – Generality: whether rule is applicable to many or limited applications (Dix et al., 2004) 13

14. Guidelines are a basis for determining a course of action: low in authority and general in application Less abstract than principles More technology oriented Principles are abstract design rules: High generality and low authority Derived from psychology, computing and sociology Require deeper understanding of human element in interaction Largely independent of technology Design Rules 14

15. Guidelines Develop a shared language Promote consistency Record best practices We will look at 4 sample guidelines 15

16. Navigating the interface Sample of the National Cancer Institute’s guidelines: – Standardise task sequences – Ensure that embedded links are descriptive – Use unique and descriptive headings – Use check boxes for binary choices – Develop pages that will print properly – Use thumbnail images to preview larger images 16

17. Organising the display Smith and Mosier (1986) offer five high-level goals – Consistency of data display – Efficient information assimilation by the user – Minimal memory load on the user – Compatibility of data display with data entry – Flexibility for user control of data display 17

18. Facilitating data entry Smith and Mosier (1986) offer five high-level objectives as part of their guidelines for data entry – Consistency of data-entry transactions – Minimal input actions by user – Minimal memory load on users – Compatibility of data entry with data display – Flexibility for user control of data entry 18

19. Android Development User Interface Guidelines Icon design Widget design Activity & Task design Menu design 19 Use a wide variety of icons Technical specs, with templates provided. Use a wide variety of icons Technical specs, with templates provided. Describes how widgets fit together with graphics templates. Describes navigation, multitasking, activity re-use, intents, and the activity stack. Describes how to arrange menu items, when to put commands on-screen, and other details about menu design.

20. Apple’s Human Interface Principles Aesthetic integrity Consistency Direct manipulation Metaphors User control 20