Download Topic 1 - IB-Design

Topic 1
1.1a Anthropometrics
Essential Idea: Designers consider three human factors to ensure products meet ergonomic needs.
Design is human centred and, therefore, designers need to ensure that the products they design are the
right size for the user and therefore are comfortable to use. Designers have access to data and
drawings, which state measurements of human beings of all ages and sizes. Designers need to
consider how users will interact with the product or service.
1.5 Design is human centred and focuses on the needs, wants and limitations of the end user
1.18 Designers must consider how users will interact with, use and misuse the products they design
1.20 Design Permeates every aspect of human experience. Individuals make design decisions in all
areas of their work, home and leisure.
International Mindedness
A wide selection of anthropometric data is published and regionalised, for example, Asian data v
European data. The designer must work with data appropriate to the target market.
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Anthropometric Data
Anthropometric Data: The measurement and
collection of data concerning the different
sizes of men, women and children.
Anthropometric data is more than a simple
measurement, it can be sub-classified as
Static Data (also known as Structural data)…...this
refers to measurements taken while while the
subject is in a fixed or standard position, e.g.
height, arm length
Dynamic Data (also known as Functional
data)…..this refers to measurements taken
during physical activities, e.g. crawling height,
overhead reach and a range of upper body
movements.
Static data is much easier to gather, as people
are asked to remain still while measurements
are taken. Dynamic data involves people
carrying out tasks. People carry out tasks in
many different ways. While static data is more
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User Populations
It is important to consider the
intended User Population for
any product (or system) you are
designing. It can be defined as
the range of users for a
particular product or system.
these can be defined by age,
gender, physical condition,
socio-economic class etc.
Population Stereotypes
Population stereotypes: responses that are
found to be widespread in a user population.
“Long-term habits and
well-ingrained knowledge that we have about
the world” (Kantowitz & Sorkin, 1983).
When walking into a room, assuming it is dark, what way would you flip a
toggle switch to turn the lights on? You have two choices, up flip or down flip.
Indeed, most Americans think that up is on but in other countries, the opposite is
true.
Making use of population stereotypes in the design of the controls for products is
relevant. It is usually anti clockwise for ‘on’ when dealing with fluids and gases
(a tap) and clockwise for ‘on’ when dealing with mechanical products (a radio).
Population stereotypes can be displaced (changed or relearned) by alternative
learnt responses, but they frequently reassert (return) under conditions of stress
such as tiredness or panic.
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Collecting Anthropometric Data
The actual data is collected using a range of different tools, sliding calipers, skinfold
calipers, fabric tapes and stadiometers.
Topic 1
Percentiles
When data has been collected and placed into a table for analysis, it is almost always going to look like
the graph shown. The graph below shows the height of a group of adults.
First, notice that the graph is symmetrical – so that 50% of people are of average height or taller, and
50% are of average height or smaller. The graph tails off to either end, because fewer people are
extremely tall or very short. To the left of the average, there is a point known as the 5th percentile,
because 5% of the people (or 1 person in 20) is shorter than this particular height. The same distance
to the right is a point known as the 95th percentile, where only 1 person in 20 is taller than this height.
So, we also need to know whether we are designing for all potential users or just the ones of above
or below average dimensions. Now, this depends on exactly what it is that we are designing.
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How are percentiles used?
Referring back to the graph on the previous page. Let's say the adult population makes up 100%,
researchers break down the group into 100 percentile groups with the first percentile being the
smallest and the 100th percentile being the largest. As designers, most of the time, it suffices to limit
ourselves to dealing with the 5th to the 95th percentile, meaning that we would cover 90 out of 100
adults.
A constant problem for designers is the conflict between designing for as wide variety of people as
possible, and, at the same time, helping the manufacturer to keep the production costs down.
For example, if we were designing a doorway using the height, shoulder width, hip width etc., of an
average
person, then half the people using the doorway would be taller than the average, and half would be
wider.
Since the tallest people are not necessarily the widest, more than half the users would have to bend
down
or turn sideways to get through the doorway. Therefore, in this case we would need to design using
dimensions of the widest and tallest people to ensure that everyone could walk through normally.
Deciding whether to use the 5th, 50th or 95th percentile value depends on what you are designing and
who you are designing it for.
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Usually, you will find that if you pick the right percentile, 95% of people will be able to use your design.
For
instance, if you were choosing a door height, you would choose the dimension of people's height (often
called 'stature' in anthropometry tables) and pick the 95th percentile value – in other words, you would
design for the taller people. You wouldn't need to worry about the average height people, or the 5th
percentile ones – they would be able to fit through the door anyway.
Topic 1
At the other end of the scale, if you were designing an aeroplane cockpit, and needed to make sure
everyone could reach a particular control, you would choose 5th percentile arm length – because the
people with the short arms are the ones who are most challenging to design for. If they could reach the
control, everyone else (with longer arms) would be able to. This should also reinforce the requirement to
ensure users can safely interact with their environments.
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Primary and Secondary Anthropometric Data
As this suggests, there are 2 forms of info. There are many many secondary sources of
anthropometric data available, both in print and on-line. This is probably where most of your
data will come from. However, if you have a particular client or access to the user population
you wish to design for, you may wish to collect measurements yourself and generate your own
primary data.
As mentioned in the first slide, it is important to consider the reliability of the data you are using or
generating. For secondary sources, is it appropriate in terms of age, gender, race or
geographic region.
If it is primary data, consider the conditions under which it was collected, were the subjects wearing
bulky clothing, or gloves? If it was a particularly hot/cold day, the measurements collected may
not be that reliable.
Topic 1
Range of Size and Adjustability
Certain products tend to be available in different sizes or with adjustability built in as there really is no
‘one size fits all’. Consider the following examples:
Clothing comes in a range of sizes. For
manufacturers to make clothing fit every
individual variance would not be
economically possible, thus it tends to
come in a range of sizes based on
percentile ranges.
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Adjustability
Ironing tables can be adjusted to allow for people of a different
height to use comfortably.
This has an effect on the design of the legs, as this is how the
board is adjusted in height.
Children’s car seats are
adjustable to allow
for a range of sizes
and a growing
child.
As are other items in a car,
such as adjustable seat
backs, adjustable leg room,
adjustable seat belts,
adjustable steering wheels,
adjustable mirrors,
adjustable headrest, etc.
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Percentile Ranges
Which user population and percentile ranges would be required
for the following products? Are all of the measurements
neccessary?
Childs Car Seat
Sitting height:
Leg room:
Arm reach:
Viewing angles:
Hip breadth:
Thigh length:
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Percentile Ranges
Office Chair
Sitting height:
Leg room:
Arm reach:
Viewing angles:
Hip breadth:
Thigh length:
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Clearance, Reach and Adjustability
Clearance
Sometimes people or machines have to move
through or work in restricted areas, for example,
maintenance work. Clearance can be seen as the
minimum distance required to, enable the user group
into or through an area. This is especially important
when designing emergency exits and safety hatches
Reach-The workspace envelope.
A 'workspace envelope' is a 3-dimensional space within which you carry
out physical work activities when you are at a fixed location. The limits of
the envelope are determined by your functional arm reach which, in turn,
is influenced by the direction of reach and the nature of the task being
performed. Most of the things that you need to use to carry out your tasks
should be arranged within this area. Workspace envelopes should be
designed for the 5th percentile of the user population, which means that
95% of users will be able to reach everything placed within the envelope.
Topic 1
Examples
What are aiming for with your design?
Design examples:
Examples of measurements to
consider:
Users that your design should
accommodate:
Easy reach
Vehicle dashboards, Shelving
Arm length, Shoulder height
Smallest user: 5th percentile
Adequate clearance to avoid unwanted contact or
trapping
Service Covers, Cinema seats
Shoulder or hip width, Thigh length
Largest user: 95th percentile
A good match between the user and the product
Seats,
Knee-floor height, Head circumference,
Weight
Maximum range: 5th to
95th percentile
Cycle helmets, Pushchairs
A comfortable and safe posture
Lawnmowers, Monitor positions,
Worksurface heights
Elbow height, Sitting eye height,
Elbow height (sitting or standing?)
Maximum range: 5th to
95th percentile
Easy operation
Screw bottle tops, Door handles, Light
switches
Grip strength, Hand width, Height
Smallest or weakest user: 5th percentile
To ensure that an item can't be reached or operated
Machine guarding mesh,
Finger width
Smallest user: 5th percentile
Distance of railings from hazard
Arm length
Largest user: 95th percentile
Topic 1
1.1b Psychological factors
Essential Idea: Designers consider three human factors to ensure products meet ergonomic needs
Nature of Design:
Human beings vary psychologically in complex ways. Any attempt by designers to classify people into
groups merely results in a statement of broad principles that may or may not be relevant to the
individual. Design permeates every aspect of human experience and data pertaining to what
cannot be seen such as touch, taste, and smell are often expressions of opinion rather than
checkable fact.
Concepts and principles:
● Psychological factor data
● Human information processing systems
● Effect of environmental factors
● Alertness
● Perception
Guidance:
● Data in relation to light, smell, sound, taste, temperature and texture as qualitative or quantitative
(ordinal/interval)
● Methods of collecting psychological factor data
● Representing the human information processing system using flow diagrams
● Applying the human information processing system to a common task
● Evaluating effects and reasons for breakdown in the human information processing system
Human error & Human Information pocessing
http://nas.psych.uidaho.edu/~ad.uidaho.edu%5Cbdyre/psyc562/readings/Human_Reliability_and_Error/Sharit(200
6).pdf
http://www.hfes.org/Web/EducationalResources/textbooksmain.html
http://psychtoolbox.org/HomePage
http://www.merlot.org/
● http://hsi.arc.nasa.gov/index.php
● http://hsi.arc.nasa.gov/web/humanfactors101/index.html
● complete these lessons from NASA
http://baddesigns.com/
http://www.ergonomics.org.uk/
Human Factors
http://youtu.be/bSK-Z6UZsIM
http://quizlet.com/6128108/option-e-human-factors-design-flash-cards/
Pedestrian urbanisation - Human Factors
http://trid.trb.org/view.aspx?id=114653
book: Human Error
http://www.google.com.hk/books?hl=en&lr=&id=CT_wFPljJEC&oi=fnd&pg=PR17&dq=human+factors+Psychological+factors&ots=SqD8UVqcwP&sig=FosbtPtezUQyiWuuhP
Topic 1
Psychological factor data
Cognitive psychology / cognitive ergonomics is concerned with mental processes, such as perception,
memory, reasoning, and motor response, as they affect interactions among humans and other
elements of a system.
In their everyday practical work ergonomists may well be more interested in improving what people do
rather than what people know or feel. However an enduring improvement of performance seems
to be possible only if the underlying cognitive representations as well as attitudes and competences
of participating persons are known. This is why, the Chomskian distinction between competence
and performance become very important for cognitive ergonomists (Amalberti, 2001).
http://www.io.tudelft.nl/fileadmin/Faculteit/IO/Onderzoek/Publicaties/Top_wetenschappelijke_publicati
http://www.slideshare.net/Liamgr/bppt-session-6-quantitative-qualitative-data
es/top10_-1/Top_10-1_Abstracts_en_Lijst_-_oud_van_IO_Campus/doc/Schiffersteinsplitmodality.pdf
This is a great example with excellent information and examples based on FOOD
Chapter 3 - Sensory Evaluation - Sung Eun Choi, PhD,ED
http://samples.jbpub.com/9781449694777/9781449603441_CH03.pdf
Topic 1
Psychological factor data
●
Data in relation to light, smell, sound, taste, temperature and texture as qualitative or quantitative
(ordinal/interval)
Noah Iliinsky provides a good, high-level description of the visual processing center in his article, “Why is
Data Visualization So Hot“:
… fundamentally, our visual system is extremely well built for visual analysis. There’s a huge amount
of data coming into your brain through your eyes; the optic nerve is a very big pipe, and it sends
data to your brain very quickly (one study estimates the transmission speed of the optic nerve at
around 9Mb/sec). Once that data arrives at the brain, it’s rapidly processed by sophisticated
software that’s extremely good at tasks such as edge detection, shape recognition, and pattern
matching.
How do we map that knowledge onto data? As we discussed earlier this semester, there are types of
measurement: nominal, ordinal, interval, and ratio. Most data that you are interested in will be one
of those four types. Mapping human capability to these levels of measurements is the key to
visualizing data. For example, we can easily distinguish between the colors blue and red (at least
most sighted people can). However, blue and red don’t have a natural ordering. There is no reason
to think that something colored red is worth more or greater than something colored blue. Color is
good at distinguishing members in a group, otherwise known as nominal measurements, but would
be a poor choice for differentiating ordered elements, or ordinal measurements. For ordinal
Topic 1
Psychological factor data - smell
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Data in relation to light, smell, sound, taste, temperature and texture as
qualitative or quantitative (ordinal/interval)
In Paul Auster’s mediocre novel Timbuktu, the human protagonist attempts to
create for his dog companion a Symphony of Smells, figuring that dogs’
strongest sense is their sense of smell, so they should be able to appreciate
odors more than colors or sounds. For humans without sight (and even those
with sight), “visualizing” data through scent can be powerful on many levels.
The main challenges, as I see them, are twofold. First, scent is subjective (I
may be weird, but I love the smell of cow manure). Scent can invoke
emotion, but the smell of fresh cut grass to a rich kid may signify the start of
little league season, while on the other side of the tracks, it may evoke
backbreaking hours cutting lawns. Second, if one could get past the
subjectivity, how would a data scientist quantify scent?
These would be important questions to answer because, according to artist Kate
McLean, we have 100% smell recall after one year, but only 30% sight
memory after three months. She would know because she has created
“smell maps” of cities around the world (her research is here:
http://www.sensorymaps.com/index.html). These beautiful, three
Topic 1
Psychological factor data
Topic 1
Psychological factor data
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Methods of collecting psychological factor data
Qualitative psychological research is where the research findings are not arrived at by statistical or other quantitative procedures.
Quantitative psychological research is where the research findings result from mathematical modeling and statistical
estimation or statistical inference. Since qualitative information can be handled as such statistically, the distinction relates to
method, rather than the topic studied.
http://youtu.be/UPCItrMUNXY
http://youtu.be/C1FQf3Rpu4c
http://youtu.be/zWmH2IGK--s
http://youtu.be/F8EyAoPyFKI
Look at and subscrib4e to: https://www.youtube.com/channel/UCK4KMPJbJSaRtRY_MxSUzlw
slideshare:
http://www.slideshare.net/manojrkasare/human-factors-topic-1-introduction?qid=65a0edb7-f8dc-4c8db4d6-2828bc82f1a3&v=default&b=&from_search=7
Taste temperature and texture , methods of
collecting psychological data
• There are 4 main scales used when collecting
ergonomic data.
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Nominal
Ordinal
Interval
Ratio data scales.
Nominal scale
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Experiments need data. To get data, a
researcher must measure something.
Measurements come in many different
varieties. For example, it is possible to
measure time, weight, length, number of
responses, height, pleasantness and
brightness. The way numbers represent a
particular measurement is called the "scale"
(scales of measurement). A nominal scale
classifies data according to a category only.
For example, an experiment may examine
which colour people select. No assumptions
are made that any colour has more or less
value than any other color. Colours differ
qualitatively from one another, but they do
not differ quantitatively. A number could be
assigned to each colour, but it would not
ordinal scale
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As with nominal scales, the labels used in ordinal
scales can be words, symbols, letters or numerals.
When numerals are used, they only indicate
sequence or order, for example, ranking someone
by placing them in a competition as “third” rather
than by a score—they may have come third with
50% right or with
75%. An ordinal scale classifies data according to
rank. With ordinal data, it is fair to say that one
response
is greater or less than another. For example, if
people were asked to rate the hotness of three chili
peppers,
a scale of "hot", "hotter" and "hottest" could be used.
Values of "1" for "hot", "2" for "hotter" and "3" for
"hottest" could be assigned. However, and this is
important, you cannot say that the difference
between the hot pepper and the hotter pepper is
the same as the difference between the hotter
pepper and the hottest pepper. It may be that you
can eat a hot pepper without feeling any pain. You
may also be able to eat the hotter pepper, but
your mouth just tingles a bit. However, the hottest
pepper is really, really hot...so hot your whole mouth
Interval scale
• An interval scale is a more
powerful scale, as the intervals or
difference between the points or
units are of an equal size, for
example, in a temperature scale.
Measurements using an interval
scale can be subjected to
numerical or quantitative analysis.
An interval scale assumes that the
measurements are made unequal
units. However, an interval scale
does not have to have a true zero.
Good examples of interval scales
are the Fahrenheit and Celsius
temperature scales. A
temperature of "zero" does not
mean that there is no
Ratio Scale
•
The difference between a ratio scale
and an interval scale is that the zero
point on an interval scale is some
arbitrarily agreed value, whereas on
a ratio scale it is a true zero. For
example, 0°C has been defined
arbitrarily as the freezing temperature
of water, whereas 0 grams is a true
zero, that is, no mass. Ratio scales are
similar to interval scales. A ratio scale
allows you to compare differences
between numbers. For example, if
you measured the time it takes 3
people to run a race, their times may
be 10 seconds (Racer A), 15 seconds
(Racer B) and 20 seconds (Racer C).
You can say with accuracy, that it
took Racer C twice as long as Racer
Representing the human information processing
system using flow diagrams
• The human information processing system can be
represented by an information flow diagram
• The arrows represent the flow of information through
the system. The boxes represent functional elements
in the processing chain, where information is
processed
Applying the human information processing
system to a common task.
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•
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The arrows represent the flow of information through the system. The
boxes represent functional elements in the processing chain, where
information is processed:
The input would be the number to be called
The sensory processes would be the eyes, which would transmit
information to the brain
The brain is the central processing unit, which examines the
information and
selects a response coded as a series of nerve impulses transmitted to
the hand and muscles, these are the motor processes
There are four fundamental assumptions – or four pillars – of the
information processing approach. These pillars underlay and support
this approach, as well as many other cognitive models.
Thinking:
• The process of thinking includes the activities of
perception of external stimuli, encoding the same
and storing the data so perceived and encoded in
one's mental recesses.
Analysis of stimuli:
• This is the process by which the encoded stimuli are
altered to suit the brain's cognition and
interpretation process to enable decision making.
There are four distinct sub-processes that form a
favourable alliance to make the brain arrive at a
conclusion regarding the encoded stimuli it has
received and kept stored. These four sub-processes
are encoding, strategization, generalization and
automatization.
Situational modification:
• This is the process by which an individual uses his
experience, which is nothing other than a collection
of stored memories, to handle a similar situation in
future. In case of certain differences in both
situations, the individual modifies the decisions they
took during their previous experience to come up
with solutions for the somewhat different problem.
Obstacle evaluation:
• This step maintains that besides the subject's
individual development level, the nature of
the obstacle or problem should also be
taken into consideration while evaluating
the subject's intellectual, problem solving
and cognitive acumen. Sometimes,
unnecessary and misleading information
can confuse the subject and he / she may
show signs of confusion while dealing with a
situation which is similar to one he / she was
exposed to before, which he / she was able
Topic 1
How environmental factors induce different levels of
alertness,
This picture shows the inside of one of
the main doors in a large commercial
jetliner. After closing the door, the flight
attendant attaches the emergency slide
on the inside of the door. After attaching
the slide, the attendant attaches this red
strip across the window. It is meant to
signal to a person outside to not open
the door. Opening the door could be
deadly since the emergency slide would
automatically inflate. It seems like it
would be very easy to forget to attach
the red strip.
The importance of controlling environmental
factors to, maximise workplace, performance
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The influence of the psychological human factors
of noise and temperature on the design of an
open-plan office
Consideration should be made for soundabsorbing acoustic partitions to keep noise of
conversations isolated. Noisy equipment such as
photocopiers and printers might be also isolated in
a separate area.
Low silent phone tones, ventilation flow, static and
dynamic tasks also need to be considered to
make the environment effective and productive.
Space is often allocated based on standardized
tasks or office status,
Office environments are more beneficial if they are
well lit with natural lighting and have some natural
influences such as the use of timber and views and
use of indoor and outdoor plants.
Office environments are more beneficial if they are
well lit with natural lighting and have some natural
influences such as the use of timber and views and
use of indoor and outdoor plants.
Assessing the impact of perception in relation to
the accuracy and reliability of psychological factor
data.
• Psychology is an area of human factors is an area of that
focuses on a range of different topics, including ergonomics,
workplace safety, human error, product design, human
capability, and human-computer interaction. In fact, the
terms human factors and ergonomics are often used
synonymously, with human factors being commonly used in
the United States and ergonomics in Europe.
• Human factors works to apply principles of psychology to
designing products and creating work environments that
boost productivity while minimizing safety issues. The field of
human factors formally began during World War II, when a
range of experts worked together to improve the safety of
airplanes.
What Makes Human Factors Psychology Different?
• Human factors psychology is generally very applied,
with most employed in this area working directly in
the field. Psychologists working in human factors
spend much of their time performing research and
applying what they know about human
behavior, perception, and cognition to create
more usable products and work environments.
Specialisms within Human Factors Psychology
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Human-computer interaction
Cognitive ergonomics
Usability
User experience engineering
Product design
Error prevention
Important Topics in Human Factors Psychology
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Cognition
Perception
Educational technology
Graphic design
Instructional message design
Human capabilities and limitations in specific work areas
The use of virtual reality in employee training
Problems that may arise from collecting this type of data
is that people’s perception can differ and often it can
give inaccurate results. Also it does not take into
account adverse or stressful situations and population
steryotypes.
Situation awareness
• is the perception of environmental elements with respect
to time and/or space, the comprehension of their
meaning, and the projection of their status after some
variable has changed, such as time, or some other
variable, such as a predetermined event. It is also a field
of study concerned with perception of the environment
critical to decision-makers in complex, dynamic areas
from aviation, air traffic control, ship navigation, power
plant operations, military command and control, and
emergency services such as fire fighting and policing; to
more ordinary but nevertheless complex tasks such as
driving an automobile or bicycle.
Topic 1
1.1c Physiological Factors
Nature of design:
Designers study physical characteristics to optimize the user’s safety, health, comfort and
performance.
(1.5, 1.18, 1.20, 2.9)
Concepts and principles:
●
Physiological factor data
●
Comfort and fatigue
●
Biomechanics
Guidance:
● Types of physiological factor data available to designers and how they are collected
● How data related to comfort and fatigue informs design decisions
● The importance of biomechanics to the design of different products considering muscle
strength, age, user interface and torque
Topic 1
Physiological factor data
Types of physiological factor data available to designers and how they are collected
When designing industrial or consumer products, physiological factors must be taken into account
ie. how users interact with products and specifically their physical comfort.
Physiological factors that affect ergonomics:
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Physical limitations
How the body moves
Hand/eye coordination
Strength
Size
Stamina - muscle strength/endurance in different body positions
Visual sensitivity ie. to light
Tolerance to extremes of temperature
Frequency and range of human hearing
Body Tolerances: How much the body can withstand when using or working with a product
Topic 1
Comfort and Fatigue
COMFORT
What is Comfort?
Comfort is of primary concern to designers. It determines how effective a design is and how well a
human can interact with a product.
Physical comfort, ie. how pleasing it feels to use a product, is one of the first things a human will notice If
something is not pleasant to the touch, people will not want to touch it or ultimately use or operate
it.
Comfort in the human-machine interface is usually noticed first. Physical comfort in how an item feels is
pleasing to the user. If you do not like to touch it you won't. If you do not touch it you will not
operate it. If you do not operate it, then it is useless. The utility of an item is the only true measure of
the quality of its design. The job of any designer is to find innovative ways to increase the utility of a
product. Making an item intuitive and comfortable to use will ensure its success in the marketplace.
Physical comfort while using an item increases its utility. The mental aspect of comfort in the humanmachine interface is found in feedback. You have preconceived notions of certain things. A quality
product should feel like it is made out of quality materials. If it is light weight and flimsy you will not
feel that comfortable using it. The look, feel, use and durability of a product help you make a
FATIGUE
mental
determination
about a product
or service. Basically
letsbe
you
evaluate
the quality
of the
Fatigue
is the
temporary diminishment
of performance.
Fatigue itcan
physical
and/or
mental.
item
and compare that to the cost. Better ergonomics mean better quality which means you will be
http://www.youtube.com/watch?v=NaWVwau_DLc&list=PLYmizvoOkKeboyjo1oJ8WhWx4EhOjK2im
How data related to comfort and fatigue informs
design decisions.
• Ergonomics and Design: Applying the Laws of Work
• Ergonomics is critical to design. Yet in spite of the fact that
many products are marketed as being ‘ergonomically’
designed it remains a widely misunderstood discipline. The
name ‘ergonomics’ means ‘the laws of work;’ derived from
the Greek ‘ergon’ (work) and ‘nomos’ (natural laws).
• Formalized in the UK after the end of World War II, it was
founded as a human performance oriented engineering
design discipline. In the United States the equivalent discipline
was called ‘human factors.’ Today both names are used
interchangeably, but ‘ergonomics’ probably has greater
public recognition because of its use as advertising adjective.
It is concerned with the understanding of the interactions
among human and other elements of a system, and the
profession that applies theory, principles, data and methods
to design in order to optimize human well-being and overall
system performance.”
What Do Ergonomists Do?
• Human technologysystem framework to analyze and help to
improve adesign. A professionally trained ergonomist will have
skills in several specific areas:
• —Physical interface design: to effectively interact with any
technology, the physical dimensions of the object must fit the
user’s anthropometric dimensions. Anthropometric dimensions
are usually expressed as percentiles and most ergonomic
designs try to satisfy a range of users, typically from a 5th
percentile woman to a 95th percentile man, for any given
dimension.
• —Cognitive interface design: knowledge of the principles of
information displays associated with the equipment, such as
warning signs, labels, instructional materials, and the
arrangement of controls (knobs, dials, etc.) are critical to
• product success. Understanding peoples’ reactions to how
something looks and their expectations about how it works are
critical components of usability.
Workplace design and workspace layout: the way
in which any work
• effort to perform the work.
Principles of optimizing
workplace layout include:
• 1) convenience—frequently
used equipment is most
conveniently located;
• 2) location—equipment can be
easily accessed without postural
deviations (bending, leaning, or
twisting); and
• 3) frequency—frequently
performed tasks are located
together.
Physical environment conditions at work:
• Job design, selection, and training: these are ways
of organizing work activities to maximize work
output and quality without adversely affecting
workers.
• —Organizational design and management:
includes peoples’ motivations and how to best
organize them into teams.
• Ergonomic Design: Application of Principles
Ergonomic Design: Application of Principles
• —Force: movement requires force, but high forces
increase injury risks. The amount of force exerted by a
muscle group also depends on the body posture.
• —Repetition: high rates of repetitive movements without
pauses for recovery can cause cumulative microtrauma
that may result in an injury.
• —Posture: every articulating joint in the body has a
neutral zone of movement that does not require high
muscular force or cause discomfort. Injury risks are
minimized when working with body segments in their
neutral range rather than outside this in a deviated
posture. Poor posture plays a central role in the etiology
of musculoskeletal injuries, and ergonomists use postural
targeting methods to evaluate product designs and
estimate injury risks.
The importance of biomechanics to the design of a given
Product
artifact
Biomechanical Factors
Reason
Topic 1
NOTES
1.
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Outline physiological factors that affect ergonomics.
fatigue
comfort
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Biomechanics - Application of forces by gravity and muscles
Anthropometry - Dimensions of the body (static and dynamic)
Biomechanics - Application of forces by gravity and muscles
Work - physiology Expenditure of energy
Environmental physiology - Effects on humans of the physical environment