2. ‘Time passes more quickly when you are busy’. Discuss the implications
of this statement from the perspective of HFE
One of the main implications of the statement are for safety in the execution of time
critical tasks. Discuss with your group the case of Mrs. Elaine Bromiley, below:
Mrs. Bromily was about to undergo a minor operation under general anaesthetic. It appears that
moments after being sedated, Elaine’s airway collapsed, preventing adequate levels of oxygen
from reaching her brain. Though potentially an emergency, the event is a recognised risk during
an anaesthetic and, as such, should be manageable.
Surgeons and anaesthetists are drilled to follow a series of steps at this point – beginning with a
non-invasive attempt to get the patient breathing normally, and ending, as a last resort, with an
emergency surgical procedure.
3. If memorisation is a skill, are we losing it because of easy access to the
internet?
This discussion topic can be initiated by asking the students to consider what they use
the internet for. We would only lose the skill of memorisation if we were using the
CHAPTER 13: DISPLAYS AND
CONTROLS
1. Discuss the use of skeuomorphs to represent functions in interactive
devices. Does it matter if the object represented by the skeuomorph bears no
physical resemblance to the referent?
Some of the early research on the design of icons in HCI looked at the use of abstract as
opposed to concrete icons, finding some advantage for the use of the former. A
2. If BEVs are almost silent when running, could you use auditory icons to
represent the state of the system and its main components? Can you think of some
original examples?
Assuming that the sound pressure levels inside the vehicle are significantly lower, then
Component/State Auditory Icon
Battery Charge state when charging
Charge in-use
3. Does the QWERTY keyboard layout have a future?
If keyboards have a future, the QWERTY keyboard has a future. It has long been
CHAPTER 14: INTERACTION,
INTERACTIVE DEVICES AND
THE INTERNET
1. Much of the debate in HFE to date has been focussed on a simple human-
machine model of a single driver in a car. What new properties and hazards will
emerge at the aggregate level with millions of automated cars interacting with the
roads and with each other, remains to be seen.
Many new properties are possible. The concept of car ‘ownership’ may become
obsolete, particularly in cities. One might buy shares in a car pool and simply summon
a car when one is needed. Collective ownership might create new hazards and a new
2. Do new technologies generate new user-requirements over above the
usability and utility of the technologies themselves?
This is a useful way to distinguish between ‘user–requirements’ and ‘system
requirements’. Users, for example, may have requirements to access information, pay
3. Search engines use complicated algorithms that go beyond merely aiding
users in their searches. Is it true that, as Elizabeth Churchill describes it, we are
shaped by the internet in terms of the reality it presents us with?
One way to approach this question is to consider the internet to be a ‘virtual ecosystem’
where we live an increasingly large part of our mental and social lives. So, as Elizabeth
CHAPTER 15: HFE IN ACCIDENT
INVESTIGATION AND SAFETY
MANAGEMENT
1. When accidents happen, it is often said that those involved were
‘complacent’. Is this really just another way of saying that they were too
trustworthy of the system (the technology and co-workers)?
More generally, it is a way of placing the focus on those involved rather than the
environment they were working in. It may well be the case that operators appear to be
2. Is it possible to compare different organisations in terms of their safety
culture?
Safety culture surveys are now offered to organisations by HFE consultancies and
others. The claim is sometimes made that, by using the same safety culture
questionnaire across organisations, organisations can compare their scores with other
It may well be possible to compare organisations within a sector in terms of their safety
culture using a standard questionnaire. Comparisons across sectors will be difficult or
even meaningless, because:
Similar items or constructs may not have the same meaning in different
sectors because of differences in social structure and organisation
3. Is ‘Human Error’ to blame for accidents? Can it ever be?
Human error may be the cause of an accident, but it need not necessarily be
blameworthy because people make errors all the time and many errors are foreseeable
and the system might have been designed to block or in some other way neutralise the
CHAPTER 16: SYSTEM
STABILITY AND
SUSTAINABILITY
1. Should ‘sustainability’ be considered a key performance indicator (KPI)
of a new system?
This is a trick question because ‘sustainability’ has to be defined in a way that can be
measured before it can be considered a KPI. Sustainability refers to the use of resources
in a way that does not deplete them and, in terms of the discussion in the latter part of
2. If you carried out a questionnaire survey and got a 40% response rate
what evidence would encourage you to believe that the findings could or could not
be generalised?
Well, it depends on what control and quality features were embedded in the
questionnaire when it was designed.
• If the survey was completely anonymous and there were no demographic or
3. Under what circumstances would it be better to interview people about
their attitudes to BEVs than to use a questionnaire?
• When the population of users is small and/or difficult to reach
• When the issues are not clear or well-understood and some exploratory research
is needed