1. Mini lecture notes, class 3
Course organization [3 min]
got group members? (put group number on hwk)
got the book?
Lego exercise [5+5]
Reprise Kegworth [15min]
How to read a book, (PQ4R) [10min]
So, preview preface, and preview conclusions soon
Chapter 1 [10]
why study the user?
risk
better design
help you be a team member/user
ABCS
not covered: emotions, esthetics
when?
How much do you have to study the user?
Chapter 2 [5]
CHI, HCI, HF, cog. Ergonomics, systems, user-centered design
Course project reminder [20 min.]
Allow chance to talk in group before talking in cybertorium

2. What causes a plane to crash?
A laundry list is required, or, a swiss cheese loaf lined up
A lot, in safety critical systems
Survey on how it’s going every three weeks

3. Kegworth Air Disaster Why? Near Ritter, Baxter & Churchill
A lovely example
Often used

4. Storyline Shut off #2 engine, RHS (the good one!)
Flight, jan 1989, Heathrow to Belfast, Midland 192
Experienced pilots, new plane (737)
Part of one of the safest systems in the world
Upon take-off, no problems
Shuddering, fire in an engine at ~10 min.
Shut off #2 engine, RHS (the good one!)
This is the pilot error

5. Hardware and Mischance
badly designed new engine, failure at 3 months, approx. t=300 h, should be t=500,000 h, not tested at altitude
/unlucky choice of diversion airport [BMI hub]
Pipedream

6. Auto throttle problem
poor mental model of plane [system] (turned off good engine, which disengaged autothrottle, solving the judder problem)
lack of engine feedback [interface design]
Pipedream

7. Vibration Dial 1 vibration dial harder to read [design]
vibration dial not required to fly [regulation]
dial and plane not trained with simulator
technology updated but not announced
Pipedream

8. Vibration Dial 2 vibration dial small [design]
Without range marking [design]
Pipedream

9. During descent lots of interruptions pilots can’t see the engines
no protocol: no checking/confirmation visually from cabin
Passengers could see fire but explained it away, perhaps also flight attendants
diffusion of social responsibilities
Social distance between aircrew and pilots

10. crash
900 m short
43+4 out of die +1 in 2012 (PTSD)

11. At crash
Not documented: noise abatement hillocks

12. Afterwards If any 13or 3 missing, no loss of life
What was the pilot error?
Thus, systems require understanding people, technology, and systems and environment

13. References Wikipedia on kegworth
BBC. (1991). Fatal error: Taking liberties [television series].
Youtube has videos as well

14. How to read a book, (PQ4R)
So, preview preface, and preview conclusions soon

15. 1.3 So, when to study the user?
Fundamental attribution error of design
More usable $$
Safer
Risk driven
Not like you
Lives at risk
Know enough given cost of knowing more (satisficing)

16. The ABCS Anthropometrics Behavioral Cognition Social System
The senses
Motivation
Cognition
Social
System
The system (pre-HCI)
The system and user (early HCI)
The system and what we know about the user (U-CS)

17. Another way to organize the user
The system (pre-HCI)
The system and user (early HCI)
The system and what we know about the user (U-CS)

18. Chapter 2