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Guide to Tutorials and Seminars
in Human Factors and Ergonomics
By
RS Bridger Ph.D.
www.rsbridger.com
Introduction
This guide accompanies the tutorial sections at the end of the chapters in the fourth
edition of ‘Introduction to Human Factors and Ergonomics’.
The material in the guide is not intended to provide ‘model’ responses to the items. The
guide provides background to the tutorial topics and the intention is to facilitate wider
debate about the material in each chapter and how it can be used. The questions are
Prologue
1. Human Factors and Ergonomics can be studied as a stand-alone
discipline but can never be applied this way.
A review of journals such as Human Factors and Ergonomics indicates that much
research is conducted at the level of core disciplines of HFE, in the form of applied
psychology, work physiology and so on. Whilst this is valuable for expanding and
One of the main themes behind the Prologue, is that HFE works best when it is in a
bigger box. This is because it is an enabling discipline that makes systems work better.
The ‘bigger box’ in the prologue is described using systems theory and some core
2. What is the difference between a system and a collection of objects?
A system has a purpose and the objects within it interact to fulfil that purpose. Systems
are bounded at any point in time, although they can evolve. Artificial systems, ‘man-
3. Your task is to consider the problem from the perspective of the agencies
responsible for the care and well-being of older people and to:
• Write, in one sentence, a single statement of user-need (SSUN) from
which
the necessary capability can be delivered; Derive the 'user-requirements'
the solution must meet. Derive the system requirements – what the system
* Hint: A user requirement may need to be met with several system requirements
and vice versa.
The purpose of this discussion topic is to guide students away from ‘solutioneering’ –
User requirements of a general nature will be of the form:
1.To obtain regular reports on the health of the target population
The first requirement might be broken down more specifically into system
requirements as follows:
1.1. Interrogate medical records database and detect changes.
1.2. Receive reports from General Practitioners on health and well-being
1.3. Process reports and identify needs
1.4. Direct needs to service providers.
Clearly, there will be many other requirements to convert into system requirements. A
CHAPTER 1. HUMAN FACTORS
AND ERGONOMICS FROM THE
EARLIEST TIMES TO THE
PRESENT
1. What impact will the 4th industrial revolution have on HFE?
Below, some suggested topics for discussion:
• Much traditional HFE (and the first 11 Chapters of the textbook!) will become
of marginal interest in 10 years and be completely obsolete in twenty. This is because
• Following the line of argument above, there will be a greater need for more
research on ever-closer integration of people with technology – human-machine
• Much of the traditional research on human information processing will also be
functioning correctly. There will be some very challenging research questions about
how to ensure the safety of such systems and whether human operators are needed at all.
• HFE specialists will have new tools for doing research in organisations. ‘Big
These are only a few of the possible discussion topics, of course.
2. Will technological change make HFE obsolete?
Discussion can be prompted by first asking the tutorial group to imagine what work
will be like in twenty years. A reasonable line to take is that HFE will not be redundant
itself, but it will look very different. Possible new lines of enquiry include:
• How will organisational culture change when groups of people are connected
via an artificially intelligent internet of things? Other potential lines of discussion are
the future research in HFE – potentially controversial topics include:
• How lifelike should robots be for optimal human-robot interaction?
3. In the year 2030, a university wishes to introduce a new course on
‘Human-Robot Symbiosis’. Discuss the main lecture topics to be covered in the
syllabus and suggest ideas for lab work and practicals (using real robots, of
course).
• Anthropomorphism: the extent to which humans will attribute human
characteristics to robots and the pros and cons of doing so. We could propose a
• User characteristics: Empathy: a measure of students’ capacity to empathise
with each other (such as a questionnaire): Age, Gender and family history
• Robot characteristics: Extent to which the robot resembles a human in physical
appearance voice etc.
• Robot engagement questionnaire: way in which the user perceives the robot.
• Safety – will people make inappropriate assumptions about the safety
constraints in place (see Chapter 15 for a discussion of safety constraints) if the
robot is ‘human-like’?
• Will people make inappropriate assumptions about what constitutes ‘common
sense’ in human robot interaction due to anthropomorphism?
CHAPTER 2. BODY MECHANICS
AT WORK. RISK ASSESSMENT
AND DESIGN
1. What is a ‘good’ posture? How would you decide?
One way to approach this is from first principles. If posture is the
‘average orientation of the body over time’ then we have to consider the
loading patterns on the body as a consequence of adopting the posture
while doing the task. Thus, a consideration of anatomical principles in
In practice, a good working posture is one which minimises the load on
the body while carrying out the task, while ensuring that operators can
2. Are biomechanical models for estimating spinal
compression too simplistic?
Probably. The main drawback is that the effects of fatigue on the tissues
themselves such that the threshold for injury is not the same at the end of
the task as it was at the beginning. In this chapter, we have only
3. Would it be possible to ‘re-engineer’ the human body when
designing lifelike robots?
Yes. If the intention was to build robots that were as lifelike as possible
then it would be possible to re-engineer the human body, particularly,
CHAPTER 3: USER-
CENTRED WORKSPACE
DESIGN USING
ANTHROPOMETRIC DATA
1. About 30 years ago, only 5% of the US or UK population were
obese. Now, over 20% are obese. Has the 95th percentile waist
circumference of 30 years ago now become the 80th percentile?
We cannot answer the question from the information provided. This is
As a tutorial topic, it would be of interest to discuss how the question might
be approached. One way, would be simply to measure the abdominal
2. If it has, how might the shape of distribution have changed?
It is likely that the distribution of waist circumference has become flatter,
Which is more likely, bearing in mind that the population itself has changed
over the last 30 years?
3. Should HFE specialists advise on how to accommodate obese
workers or just tell them to lose weight?
HFE specialists should not tell obese workers to lose weight because they
CHAPTER 4: POSTURE,
MOVEMENT AND
WORKSTATION DESIGN
1. If you were to follow-up the Garrett et al. study, how would you find
out whether improved productivity was due to standing per se or due to a
reduction in discomfort that might be achievable in other ways?
One way would be to consult users – just ask them. A more systematic approach
might involve a trial over a period of time and at which users worked at
conventional or 'sit stand’ workstations. Data on body discomfort might be obtained
2. ‘Humans are not designed to stand or sit, they are designed to walk’.
Discuss.
Review the evolutionary material at the beginning of the chapter. The lumbar
lordosis is an adaptation to bipedalism which enables the trunk to be extended in line
with the legs leaving sufficient space for a striding gait. Together with other
3. ‘In twenty years’ time, office chairs and desks will be obsolete?’
Discuss.
There are several different ways of approaching this question, depending on the
focus:
1. Office work will continue but office design will be different. People will
work using laptops and other devices such as wearable computers. Therefore, there
CHAPTER 5: REPETITIVE
TASKS. RISK ASSESSMENT AND
TASK DESIGN
1. Does ‘RSI’ exist?
No.
2. If a worker experiences pain at work it must be the work that caused
it? Discuss.
The question is designed to stimulate discussion about the concept of ‘work-
relatedness’. With non-specific health outcomes, the experience of pain is often
linked to several different factors, including the propensity to report pain, which, in
turn, may be linked to psychosocial factors. The categorisation scheme at the
beginning of the chapter is a good place to start the discussion. Where the question
becomes into sharp focus is in legal cases involving claims for disability. Here, the
lawyers acting for the claimant will try to show that the pain (or the condition
causing the pain) was caused by work and that the employer was negligent. Lawyers
acting for the defendant will try to show that the pain was not caused by work or is
not real. HFE specialists sometimes work as expert witnesses in such cases and can
help to provide evidence to answer three questions:
3. ‘People should finish work in the same state of health as when they
started’. Discuss.
This is an important point to understand because it relates to the concept of
occupational overuse injuries. Where there is room for debate is in the definition of
the work ‘health’. If one takes ‘health’ to mean the absence of disease then feeling
tired after work is not necessarily a sign of ill-health. However, if one regards health
CHAPTER 6: DESIGN OF
MANUAL HANDLING AND LOAD
CARRIAGE TASKS
1. How do competitive weight lifters manager to lift such heavy loads
without injury?
• Training
• Technique
• Low rates of exposure
Competitive weight lifters are only exposed to maximum loading on specific occasions,
2. Robots should do all the lifting in future?
The trend to mechanise and automate manual work is likely to continue, not least
because manual handling is inefficient and does not add value to products. To
understand the ‘big picture’ review the discussion of containerisation in the prologue
3. Why don’t we carry things on our heads anymore (in 21st Century
Western countries, at least).
If you look at old paintings of Europe hundreds of years ago, where working scenes are
depicted, it is not unusual to see laborers or farmworkers carrying loads on their heads.
Head-load carrying was common in Europe before the Industrial Revolution. It appears
to have died out with increasing mechanization and (maybe) for social reasons, where it
CHAPTER 7: WORK CAPACITY,
STRESS, FATIGUE AND
RECOVERY
1. Is the work capacity of the population changing?
According to some researchers, it is changing and the work capacity of the population
is lower than 50 years ago. The main reasons are: the increase in overweight and
obesity which adds an additional cost to any task requiring movements such as walking
2. Should work be made less demanding through automation and the use of
job aids?
Traditionally, ergonomists and human factors specialists focussed on ‘lowering the
load’ at work because demands were often excessive or inappropriate and the result of
