Understanding The Reasons Behind Errors

Posted in human factors on October 28, 2022 by Paul Armstrong ‐ 4 min read

Understanding The Reasons Behind Errors

As part of my journey to be a better instructor, I’m taking continuing education in Human Factors. This is a topic that’s been near and dear for some time, so you can expect to see this topic pop up quite a bit.

One of the ways in which we, as humans, have a tendency to block of learning is through how we ask questions. We’re going to explore the reason for using how instead of why.

Primarily if the person who’s on the receiving end of the question feels under attack (or that they might soon be), they’re likely to be defensive and withhold information. This makes means we miss out on the ability to learn from what actually happened and potentially avoid it in the future.

So, how do we ask questions?

Avoid why?

Imagine you’ve just gotten out of a somewhat harrowing situation where a mistake was made. Your blood is pumping and there’s a thousand things going through your head.

Am I going to be blamed for this?

What did I do that for?

Will I still have a job tomorrow?

How close did we really come to injury or death?

And many more. If you’re working in a place where people are bullied or otherwise has a blame oriented culture, then “did anyone notice” will also likely be at the forefront of your mind.

Then someone comes up to you and says “Why’d you do that?”. Even if they truly want to understand, our natural reaction is to feel under attack and respond defensively. It comes across as asking us to justify our positions. Often, especially under stress, we will make up reasons or try to answer in the way that we believe the person asking the question wants to hear or to shift blame. We may also just shut down and respond with “I don’t know”.

Use how

Conversely, if someone comes up to you and says “That must have been quite a shock. Can you please help me understand how it made sense to do that?”, we have a totally different emotional reaction. Firstly, the questioner is recognising the emotion involved. Then they’re asking an open ended question which seeks to understand what was happening without the undercurrent of blame.

A Story

A dive instructor does a dive in the morning to 25 meters using a 36% nitrox mix. Later that day, they have a dive to 35 meters. It’s been a hectic morning and as the boat is about to leave, they realise that they’ve still got their old tanks setup. Taking a quick look at their SPG, they notice 150 bar in their twinset. More than enough for the quick dive they have planned, they’re not a particularly heavy breather and it’s a short dive. So, rather than holding the boat, they jump on and head off to the dive site. After the dive, while they’re packing up their gear, they notice their nitrox stickers. Rattled, they head over to talk to their manager who raises and eyebrow, gives them a nod, and says “you’ll never do that again”.

After the customers have left, the team sits down to debrief the day. “What lead to that making sense?” they ask. They go over the time crunch and the SPG check, along with not reading the maximum operating depth stickers. The team decides that they’re going to change the shop policy, writing down the planned dive depth and gas maximum operating depth for each diver on the boat as part of the dive masters pre-departure checklist.

If you didn’t spot the problem (or haven’t done nitrox training), the calculation for maximum operating depth of a gas is as follows:

$$ \begin{equation*} \bigg[ \bigg( \frac{maximum\ partial\ pressure} {percentage\ of\ oxygen,\ as\ a\ decimal} \bigg) - pressure\ from\ air \bigg] * meters\ per\ bar \end{equation*} $$

So, for 36%, we have:

$$ \begin{equation*} \bigg[\bigg(\frac{1.4}{0.36}\bigg) - 1\bigg] * 10 \end{equation*} $$

This gives a maximum operating depth for the gas they were breathing of 29 meters.

In this instance, the team learned a lot and changed their standard operating procedures. By adjusting their divemasters checklist, they’re making sure gas and depth checks are done by an extra person and limiting the possibility for this kind of issue to occur in the future.