Lecture 17: Human Error (Part I)

Question 1

Human Error examples:

Answer 1

• Trader hit “B” for billion instead of “M” for million

- ‘Erros often happen because we are not paying attention”

Question 2

We are all human + humans make mistakes = ?

Answer 2

• We all make mistakes

Question 3

The four types of human error:

Answer 3

• Mistakes (Blue) : intended actions
• Slips
• Lapses
• Violations (Blue) : intended actions

Question 4

What are mistakes?

Answer 4

• Actions run according to plan

- The plan is deficient

Question 5

What are violation?

Answer 5

• Deliberate departures from safe practice

- Sabotage to ‘normal’ violations

Question 6

What are slips?

Answer 6

• Actions-not-as-planned

- E.g. wipers instead of indicator

Question 7

What are lapses?

Answer 7

• Omission of action: e.g. forgetting to turn stove off

- Forgetting intentions

Question 8

Slips only occur during…

Answer 8

• The performance of skilled behaviour:
• Speech (Freud) or
• Practiced actions

Question 9

What are the three stages of development?

Answer 9

• Cognitive or knowledge stage
• Associative or rule stage
• Autonomous or skill stage

Question 10

Closed-loop control requires close attention to monitor feedback about error, no spare capacity…

Answer 10

• Input
• Processing
• Output
• (Feedback)

Question 11

Open loop control depends on occasional error checking. Spare capacity for other tasks

Answer 11

• Input
• Processing
• Output