Monday, 29 July 2013

What's in a word?

The words we use allow us to think and talk about concrete things (such as cars) and abstract concepts (such as love). Although it depends on the definition of the word "word", today there are either 600,000 or over 1 million words in the English language, with the number of words increasing at the rate of 8500 per year. Depending upon education and literacy, a person will know between 35,000 to 75,000 words.

Language shapes our world

The language we use helps us to communicate with one another. Even more than that, the language we use both affects and reflects how we see the world. This is called "linguistic relativity". To show how language affects how we see the world we need only think about terms such as "global warming" and "credit crunch". These concepts express previously unknown dangers which affect how secure we feel about our own and our children's futures.

"Piegnartoq”: the snow [that is] good for driving sled
Language also reflects the importance we attach to certain ideas or things. For example, the Inuits have more than 50 distinct words for snow, reflecting the importance of this substance in their culture. (Although there is controversy regarding the exact number of words.)

The exclusion of particular words in a language system also implies a framework of values to the language users. When a behavioural marking system such as Anaesthesia Non-Technical Skills (ANTS) lists the behaviours expected of a good anaesthetist, these are endowed with added importance and those behaviours not listed may be considered to be less important. The idea that our language limits and determines our ability to think is called "linguistic determinism".

As an example of how language may affect thinking, let us imagine two new words: 
  • Sladen
  • Quaden
Sladen means the leadership required by a person in charge of strategy and long-term effects. Quaden is the leadership required when decisions are needed immediately with little or no information. One could use these terms to discuss a given individual's strengths and weaknesses, or to compare the characteristics of those who have one or the other type of leadership. The use of these new words would affect how we think about leadership. The words would also reflect our thinking, in the sense that we are interested enough in leadership for us to want to discern different types. (I'm using Sladen and Quaden as fictitious examples and am aware that terms such as "strategic leadership" already exist.)

The language of human factors

The language of human factors allows us to be more precise about what went well and what we found to be a challenge. If you have a teaching role then the human factors vocabulary will allow you to move from: "Well, that was terrible, wasn't it?" to "Your main problem was that you lost situational awareness when you volunteered to take over chest compressions." Learning the human factors vocabulary and concepts will also allow you to reflect both more effectively  and more efficiently on your own performance. For example, in the language of human factors, errors may be divided  into slips/trips, lapses, mistakes and violations. These types of errors have different causes and therefore different remedies. But without the vocabulary, a mistake is a mistake is a mistake; your ability to  improve yourself and others will be compromised.


Spreading the word(s)

Many religions have missionaries who "spread the Word". Although I don't equate patient safety or human factors with a religion, I would suggest that one of the activities that those of us involved in these fields should be doing is "spreading the word(s)". J├╝rgen Habermas reasoned that all speech acts have a goal, ie. by talking we are trying to have an effect on the world around us. The goal for us in the patient safety arena should be a wider understanding of the words and concepts which define human factors. With this vocabulary, the rest of the healthcare community and the people we care for will be better able to reflect, understand and discuss our failings and successes. Without this vocabulary we will be less able to improve the care we provide. Let us help transform the healthcare system so that when we talk about "hindsight bias", "power gradient" and "task fixation" every HCA, every nurse, every chief executive knows what we mean.

Thursday, 25 July 2013

Book of the month: Set phasers on stun by Steven Casey

The subtitle of Dr. Steven Casey's book explains its appearance on this blog:

And other true tales of design, technology and human error.

This book is an easy holiday read which does not tax the mind. The chapters, wich consist of 18 stories of human-technology/design problems, are independent of one another and can therefore be read out of sequence. As a reminder that human error and human-technology interface problems can be found wherever the two come into contact, this book suits both the general reader and the human factors devotee. 


Casey is the president of Ergonomic Systems Design, Inc. and an associate editor of "Ergonomics in Design" a publication of the Human Factors and Ergonomics Society (HFES). He read psychology and engineering at the University of California and North Carolina State University.

Published in 1993, Casey's book preceded the Institute of Medicine's landmark report "To Err is Human" by six years. In many ways this is a book which presaged the current interest in human factors in Medicine. This book focuses on the "incompatibilities between the way things are designed and the way people perceive, think, and act." 

Casey provides eighteen stories which he hopes will teach "a lesson about people, about the design of things, and about the necessity of addressing this all-important component of technology." The stories are well-written and engrossing, however there is very little exploration of human factors or human error. Do not, therefore, expect an expansion of your human factors vocabulary or theoretical constructs. 

Every story, except one, quotes a number of references to back up the dialogue and sequence of events. The story lacking references "Double Vision" (p.152-160) does not explain why these are lacking, although the suggestion from the author's prologue is that these events were witnessed by one of the protagonists. This person must then have relayed the story to Casey.

A potential use of this book may be to present one of the stories to an audience and ask them what human factors are illustrated therein. This may be of particular use if you have already covered the dancing gorilla and the "battleship vs lighthouse" scenario. For example, the chapter "A Memento of Your Service" tells the story of Pastrengo Rugiati, a captain of an oil tanker who has a deadline for docking at the oil terminal. If he fails to meet the deadline he will have to wait another six days before he can make another attempt. His ship has drifted off course, there are fishing boats in the area and he is taking a route he has never sailed before. This is the sort of complex, dynamic, stressful situation which we often encounter in healthcare and the parallels may be drawn by a human factors audience.

The book also illustrates the value of in situ simulation for stress testing. In the chapter "Return from Salyut" Russian cosmonauts have to close a valve on their spacecraft as it re-enters the atmosphere. Unfortunately the amount of time it takes to close the valve exceeds the amount of time available before the cabin depressurises. In situ simulation allows the healthcare community to test for these design failures in both equipment and processes.

At times Casey illustrates some of the characteristics which are perhaps frowned upon in human factors. For example in the above oil tanker story, Casey talks about the two fishing boats Rugiati has to worry about:
Actually, these were two French "crabbers" working the shallow waters of the shoals. This alone should have alerted the supertanker crew of the danger ahead. (p.52)
The subtext is that the crew should have recognised the fishing boats as "crabbers" but there is no indication as to how likely this is. On p.147 Casey talks about the "inevitable" shift of sea water within the Herald of Free Enterprise, a term that Sidney Dekker frowns upon. Dekker would argue that the word "inevitable" reflects old-school thinking about human error, where a sequence of events leads to an inevitable conclusion.

Although Casey's thesis is the need to be aware of the role of ergonomics in human error, the word "ergonomics" is never used and the argument is not developed. Many of the current concepts and vocabulary in human factors, such as situation awareness, shared mental model, task fixation, etc. are never mentioned. It is possible that this is because the book was written in 1993, however an introduction to the vocabulary of ergonomics would have been a useful addition for the novice reader.

A couple of additional complaints are:
  • The size of the footnotes. At times these take up half the page (p.51) and it is often unclear why these footnotes are not embodied within the text.
  • The lack of diagrams/illustrations. For example, on p.121-122 Casey uses a considerable number of words to explain the structure of an SL-1 reactor and on p.170-171 he describes the routes of a number of warships off the California coast. In both instances, simple diagrams would have been helpful.

Although wary of making this into a good news/bad news/good news "sandwich", none of the above criticism should stop you from borrowing (not buying) this book. The stories are interesting, from a wide range of industries and will provide you with additional fodder for your human factors workshops/talks.