User Interface Responsiveness Instantaneous Immediate Continuous Captive

1. InfoCamp 2009 User Interface ResponsivenessInstantaneousImmediateContinuousCaptive Steve Seow| User Researcher | Microsoft Surface Rajesh Kalidindi | User Researcher | Microsoft IT

2. About Steve… • Academic: Experimental Psychology • Human Timing, Time Perception, Human-Computer Interaction • Professional: User Researcher • Microsoft Surface • Spare time: Author • Designing and Engineering Time

3. About Rajesh… • Academic: • Economics, PG in Computer Applications • Certified Usability Analyst • Professional: User Researcher • Microsoft IT • Spare time: • Observe

4. Overview… Barnabus Effect Defining Responsiveness Classes of Responsiveness

5. The Barnabus Effect… Clip 1

6. The Barnabus Effect… Clip 2

7. The Barnabus Effect… • WYSMNBWYG: • What you see may not be what you get! • 2. Your brain plays tricks on you all the time! • … so don’t trust your brain! • Scholarly note: Look up Attenuation Hypothesis

8. defining... • relsponlsivelness

9. relsponlsivelness • the ability of a system to respond to user input and process internal operations without undue delay.

10. Responsiveness is… • 1. relativeto the interaction in question • Reflex < Reaction < Verbal Acknowledgment • Key press < Local search < Large Data download • 2. subjectivelyperceived & interpreted • A two-hour documentary = boring or captivating? • Two-hour virus scan = good or bad? • 3. non-exclusivein its form • Street signs : Landmarks, structures, etc. • Notification: HDD thrashing, LED blinking, etc.

11. Industry Standards 1472 = MLT-STD-1472F C = Card et al (1990) ESD = ESD/MITRE M = Miller (1968)

12. Metric A Interaction A Metric B Interaction B Metric C Interaction C ? Interaction C Version 2.0

13. Metric Interaction Interaction Metric User Expectancy Interaction Interaction

20. Range of maximum acceptable response time What users expect 0.1 to 0.2 sec Instantaneous 0.5 to 1 sec Immediate 2 to 5 sec Continuous 7 to 10 sec Captive

21. introducing... • classes of • relsponlsivelness

22. 1. Instantaneous (< 0.1 – 0.2 sec) • Users Expect: Instantaneous behavior • Analogy: System’sNerves, Senses, etc. • R.o.T: Anything that mimics physical objects • Examples: Key-press, GUI button press, etc. RoT: Rule of Thumb

24. 2. Immediate (< .5 – 1 sec) • Users Expect: Acknowledgement • Analogy: Reflexes, Simple Reaction • R.o.T: “No-brainer”* operations • Examples: panning, zooming, viewing “processed” or ready* data • * = as perceived by users!

27. 3. Continuous (< 2 – 5 sec) • Users Expect: Uninterrupted Flow • Analogy: Thinking Time, “Calculated” Reaction • R.o.T: Periodic progress update, error messages • Examples: error messages, time-outs, progress indication

29. 4. Captive (< 7 – 10 sec) • Users Expect: NOT to be held hostage or stay idle • Analogy: System Elevator Pitch • R.o.T: Attention Span • Examples: Downloading, Delivery of consumable information (status, etc.)

31. Responsiveness Classes • Not mathematical model based on a continuum of “slow to fast”, letter grade-assignment, etc. • 0 to 1: Superfast. • 1 to 2: Fast. • >2 Slow! • Psychological, empirical model based on what users expect. • So “gaps” are possible (0.1 to 0.2, 0.5 to 1) • Even overlaps could have been possible!

32. Summary • Defining Responsiveness • Relative • Subjective • Non-Exclusive • Classes of Responsiveness • Instantaneous • Immediate • Continuous • Captive

33. Thank you! • More Info? • Steve - SSeow@Microsoft.com • Rajesh - RaKalidi@Microsoft.com • Blog - http://blogs.msdn.com/time • Book - Designing and Engineering Time • Web - www.Engineering Time.com • Handout: UI Timing Cheatsheet