Decision Making – Making Sound Decisions

Facts of Kegworth: an example of poor diagnosis

8 January 1989

After departing Heathrow bound for Belfast, as the Boeing 737-400 was climbing through 28300ft, the outer panel of the fan on the no1 engine detached. This gave rise to a series of compressor stalls on the number 1 engine, which resulted in airframe shuddering, ingress of smoke and fumes to the flight deck and fluctuations of the number 1 engine parameters. 

Believing that the number 2 engine had suffered damage, the crew throttled back the number 2 engine and subsequently shut it down. The shuddering caused by the number 1 engine reduced as soon as the number 2 engine was throttled back which persuaded the crew that they had dealt correctly with the emergency. They then shut down the number 2 engine. Although at this time they also commenced a low powered descent, which further confirmed their decision, with reduced vibration and smoke. The number 1 engine operated apparently normal after the initial period of severe vibration and during the subsequent descent.

The crew diverted to East Midlands airport for a Runway 27 instrument approach.

The approach continued normally. However, when power was required on the number 1 engine, a high level of vibration occurred followed by an abrupt reduction in power and then a fire warning. This occurred at 2.4NM from the runway. Efforts to restart the number 2 engine were not successful. The 737-400 hit the embankment 630m short of the runway threshold. Luckily, no cars were on the motorway at the time.

47 passengers died, 74 suffered serious injury.

Bias: A bias is anything which incorrectly skews a perception
There are many types of bias. We’re going to look at these four types

1. Confirmation or Expectations bias
2. Tunnel Vision or Fixation
3. Group Think
4. Overconfidence bias

Confirmation / Expectation bias

• Paying more attention to what we think we know and what we expect to see rather than the information in front of us.  
• In other words, we pay more attention to what we think we know about the situation, drawing from our past experience of similar events, than we do from the factual situation confronting us
• We hear what we expect to hear, and see what we want to see.

To avoid confirmation bias: seek out people and information that challenge your opinions, or assign someone on your team to play “devil’s advocate”.

Which decision methods are more prone to confirmation/expectation bias? Creative, Analytical, Rule based and/or Intuitive? 

Intuitive, as this method occurs within your mind. i.e. it is not check with others unless time is available.

This bias makes us place too much faith in our own knowledge and skills.

93% of US drivers believe they are in the top 50% of drivers

Svenson, 1981

Overconfidence bias

• This happens when you place too much faith in your own knowledge and opinions.
• You may also believe that your contribution to a decision is more valuable than it actually is. 

To avoid overconfident bias: 

Consider the following questions:

• What sources of information do you tend to rely on when you make decisions?
• Are these fact-based, or do you rely on hunches?
• Who else is involved in gathering information?
• Has information been gathered systematically?

Note: It’s hard to spot psychological bias in ourselves, because it often comes from subconscious thinking.

For this reason, it can often be unwise to make major decisions on your own, instead important decisions should use a group process and listen to all perspectives

Group Think  occurs when a highly cohesive group reaches consideration without fully considering all the alternatives and risks. 

More important to be accepted by peers than to make a hard decision.

Which decision methods are more prone to group think? Creative, Analytical, Rule based and/or Intuitive?

Analytical and Creative.

Sometimes its hard to speak up against a senior person’s decision, however everyone is human and we all make errors. Beware of blindly following the leader.

Focusing attention only on the ‘most important’
task, lose sight of big picture.

OR

Getting obsessed with a particular task or piece of equipment that isn’t as important.

Attentional Narrowing

Stress can impact our thought processes, particularly our attention and perception of information, reducing our focus on peripheral or less relevant information and increasing our capacity to focus on important information associated with the main task. This is referred to tunnel attention.

A person’s perception of what is important is strongly associated with what is considered relevant or what is a threat.

Depending on the situation, tunneling of attention can either enhance or reduce performance.

For example if information or cues are considered irrelevant to achieve a task or outcome, the ability to disregard or tune this out is likely to improve performance.

However when information or cues are related to the task and would lead to task success, performance suffers when this information is not considered.