T1 Human factors and ergonomics for IB Design.pptx

Topic 1 Human measurements for IB Design SL

1. 1.1 Anthropometrics Design is human centred and, therefore, designers need to ensure that the products they design are the right size for the user and therefore 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. Use and misuse is an important consideration. Concepts and principles: • Anthropometric data: static and dynamic data, structural and functional data • Primary data versus secondary data • Percentiles and percentile ranges • Range of sizes versus adjustability • Clearance, reach and adjustability Essential Understanding: • Collecting anthropometric data considering reliability and limitations • Interpreting percentile tables for user populations • Design contexts where different percentile ranges are used You as a designer: As a designer you need to appreciate how anthropometric data sets can vary significantly between populations. Particularly in the fashion industry, the variance in these data sets impacts the size range of clothes for particular markets. Essential Idea: Designers consider anthropometrics to ensure products meet ergonomic needs.

2. Human Factors “Human factors” and “ergonomics” are interchangeable terms—the term “human factors” is more commonly used in some parts of the world, such as the United States (US), and the term “ergonomics” is more widely used in other countries. Human factors analyses the interactions between humans and other elements in a system, and then applies principles, information and data to a design to maximize human well-being and system performance. Human factors design ensures that products, organizations, environments and systems are compatible with the needs and limitations of people. The term Human Factors is used for the combination of ergonomics and anthropometrics Human Factors is also known as comfort design, functional design, and user-friendly systems, is the practice of designing products, systems or processes to take proper account of the interaction between them and the people that use them. Ergonomics: The application of scientific information concerning the relationship of human beings (shape) to the design of objects, systems and environments. Anthropometrics: The aspect of ergonomics that deals with body measurements , particularly those of size, strength and physical capacity. Human Factors aims to: Reduce stress and fatigue on people, as they will be able to do things faster, more easily, more safely and make fewer mistakes (reduce errors) Increase safety Increase ease of use Enhance operational comfort Improve system performance, reliability and maintenance

3. Anthropometrics Anthropology, the study of humans and metrics is all about sizes. So, Anthropometrics is the study of the different sizes of people. Knowing the sizes of people and their body parts, aids designers to develop products and spaces which are comfortable or adjustable and increase the ease of use. Design is human centred. Therefore, designers need to ensure that the products they design are the right size for the user and 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. Use and misuse is an important consideration.

4. Anthropometric Data Anthro·pom·etry. This is the branch of ergonomics that deals with body shape and size . People come in all shapes and sizes so you need to take these physical characteristics into account whenever you design anything that someone will use, from something as simple as a pencil to something as complex as a car. All designed products and environments have users who interact with the finished product. It can be argued that the easier and more “comfortable” this interaction is made, the better the product. Anthropometric Data: The measurement and collection of data concerning the different sizes of men, women and children. Anthropometric data sets can vary significantly between populations. Particularly in the fashion industry, the variance in these data sets impacts the size range of clothes for particular markets. Read this article

5. Types of Human Factors 1. Physical ergonomics 2. Cognitive ergonomics 3. Organizational ergonomics

6. Static and Dynamic Anthropometric Data Anthropometric data is more than a simple measurement, it can be sub-classified as 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 reliable, dynamic data is often more useful. Static Data ( also known as Structural data ) 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) refers to measurements taken during physical activities, e.g. crawling height, overhead reach and a range of upper body movements.

7. Static Anthropometric Data Specific Body Part Product Circumference of head. Top of head to bottom of chin. Motorcycle Helmet http://www.championmoto.tk/?product=agv-project-46-all-sizes Sunglasses Static Data ( also known as Structural data ) refers to measurements taken while while the subject is in a fixed or standard position, e.g. height, arm length Static (Structural) Anthropometry includes: Skeletal dimensions – measurements of length of bones between joint centres. This includes soft tissue measurements for example the wobbly stuff that covers our bodies - muscle, fat, skin, bulk. Doesn't include: Clothing or packages. Interesting note- First measurements of static anthropometry were done by a Belgian mathematician called Quetelet in1870. Task 1: Anthropometric Static Data Write a list of body parts which could be measured and suggest a product that this measurement could be used for.

8. Dynamic Anthropometric Data Dynamic Anthropometry “…… deals with measurement that relates to the measurement of range or reach of various types of body movements. Usually when people work more than one body part they move in concert to give the body the desired nature and reach of movement. For example when a person may stretches out to reach an object by bending towards the object as well as extending the arm. It may further involve twisting of the back and waist. Perhaps the person may also raise one leg to extend the reach. Dynamic anthropometry data is used in designing systems that take into account the limits to the reach of such body move ment. For example, the shape of a work bench used for assembly of parts, may be designed so that all the parts and tools used during the assembly can be reached by the operator conveniently.” Dynamic (Functional) Anthropometry is the distances that are measured when the body is in motion or engaged in a physical activity. Reach (e.g. could be arm plus extended torso) Clearance (e.g. two people through a doorway) Volumetric data or kineosphere (The concept of a "kineosphere" is defined as the “space which can be reached by easily extended limbs”. This concept has been used widely and variously described such as "gestural space" and "zone of reach" Task 2: Dynamic Anthropometric Data Take one of the products from Task 1 and prepare a 3 minute presentation on how anthropometrics have influenced the design of the product. This may be backed up with interesting information / presentation you have researched. (see link for further examples) Dynamic Data (also known as Functional data) refers to measurements taken during physical activities, e.g. crawling height, overhead reach and a range of upper body movements.

9. Dynamic Anthropometric Data Dynamic Data (also known as Functional data) refers to measurements taken during physical activities, e.g. crawling height, overhead reach and a range of upper body movements. Task 3- Dynamic Anthropometric Data Consider the amount of movements that a driver of a car makes, with different parts of the body. Discuss with a partner what measurements would need to be taken and why? For example: When designing the pivoting action of an accelerator pedal the angle of movement that the ankle can comfortably make would have to be measured.

10. Percentile ranges Around WWII, Henry Dreyfuss Associates started to develop anthropometric guidelines for designers using data gathered from other sources, which are inherently biased since most are still culled from the military. The primary difference was that this data was being generated to allow designers to apply human factors information to design consumer products. Of course it doesn’t always follow that the curve will be a ‘normal’ bell-shaped one – it may be ‘skewed’ to one end – if for example the distribution curve of people within a primary school were surveyed. As there would be many small children within the sample, the curve would be towards the ‘shorter‘ end. So aiming a product at a particular group of people needs to use anthropometric data such as this before it is designed. Henry Dreyfuss In regards to the above types of data, you need to demonstrate understanding of what they are, the differences between them, how they can be used within context and how they are measured. The 5th percentile mark is the point below which 5% of the population is represented in the graph The 95th percentile is similarly the point above which the tallest 5% of the population are represented Predictably the 50th percentile mark is the point at which 50% are below that height and 50% are above. The line down the middle in this case is the most common height found in the sample – this the ‘modal height’. Since this curve is symmetrical – the ‘average’ height is also shown at the line in the middle – so the ‘mean’ height point coincides with the ‘median‘. Percentile ranges Measurement of Man & Woman

11. 95th Percentile 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. 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. 5th Percentile

12. Percentile ranges A wide selection of anthropometric data is published and regionalized, for example, Asian data versus western European data. The designer must work with data appropriate to the target market. T ask 5: Percentile range Sidi- a famous italian cycle shoe company which originally opened in Italy is now going global. Outline how anthropometric data can help determine the stock sizes needed if you open shops in the US and Asia. Predict what shoe size range would be needed in both shops. Explain why increasing globalization and migration of people may make stocking of international shops more difficult in the future.

13. Percentile Range Describe a design context where the 5th–95th percentile range has been used Describe a design context where the 50th percentile has been used Explain the limitations of using the 50th percentile as a means of designing for the “average” person Identify specific design contexts where the designer would use percentile ranges for particular user groups.

14. Percentile Range Describe a design context where the 5th–95th percentile range has been used For example, in mass-produced clothing or an adjustable car seat, an office chair, a bike with a seat adjustment. In the case of clothing a range of sizes has been manufactured such as small, medium or large as there can be no method of adjustment like in an office chair. Describe a design context where the 50th percentile has been used For example, height of a desk, washing machine, kitchen counter – designed for average people. This is suitable to the majority, who are close to average height, but this is necessarily a compromise for very short or tall people. Explain the limitations of using the 50th percentile as a means of designing for the “average” person The 50th percentile refers to one particular dimension. For example, someone may be average in height but not average in other dimensions. Supposing you were to design a doorway according to the height and bodily breadth (shoulders, hips, etc.) of the average person. Fifty percent of people would have to turn sideways to get through it. Since the tallest people are not necessarily the broadest, our design would inconvenience more than half the user population Identify specific design contexts where the designer would use percentile ranges for particular user groups. For example, toys for young children. Mass produced clothing (different dress sizes) & Children’s Toy age groups.

15. Percentile charts There is a great deal of anthropometric data available and you are expected to be able to: interpret percentile tables in order to calculate dimensions related to a product and consider how products can be adaptable for different markets or adjustable to cater for most consider the 5th, 50th and 95th percentiles in particular, and percentile ranges such as 2.5th to 97.5th and 5th to 95th interpret percentile tables based on different national and international populations, gender and age.

16. Primary and Secondary Anthropometric Data 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. It is important to consider the reliability of the data you are using or generating. Make sure when using data from 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. Primary anthropometric data Secondary anthropometric data Primary anthropometric data collection (also called field research) involves the collection of data that does not already exist. This can be through numerous forms, including questionnaires and telephone interviews amongst others. LINK Secondary anthropometric data collection (also known as desk research) involves the summary, collation and/or synthesis of existing data rather than primary data, where data is collected from, for example, research subjects or experiments. Consider how a product you have used recently, has failed you due to poor anthropometric considerations by the designer. As a designer you have been asked to design a baby’s high chair. What primary and secondary anthropometric data would need to be collected in order to design the chair so that it was suitable for all potential users?

17. Collecting Anthropometric Data Tools used: Unreliability may have arisen from the tools used to perform anthropometry Personnel training: anthropometric techniques are prone to errors that could arise, for example, from the inadequate training of personnel Time of the day: because the cartilaginous discs of the spinal column get compressed by body weight throughout the day we tend to be slightly shorter in the evening up to 22mm Person’s body shape: problems from collecting accurate data from nude or clothed people ( people work with shoes and cloth) Users do not carry tasks in the same way: so data may be unreliable when observing user behaviour Obtaining static data is straight forward: but users interact with products and systems dynamically making accurate data gathering difficult to obtain. Here are the reasons why it is sometimes difficult for you to collect accurate anthropometric data mainly due to the reliability and limitations available.

18. Percentile ranges What is it that you 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 Manholes, Cinema seats Shoulder or hip width Thigh length Largest user: 95th percentile A good match between the user and the product Seats, Cycle helmets, Pushchairs Knee-floor height Head circumference Weight Maximum range: 5th to 95th percentile A comfortable and safe posture Lawnmowers, Monitor positions, Work surface 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, Distance of railings from hazard Finger width Arm length Smallest user: 5th percentile Largest user: 95th percentile Sometimes you can't accommodate all your users because there are conflicting solutions to your design. In this case, you will have to make a judgment about what is the most important feature. You must never compromise safety though, and if there is a real risk of injury, you may have to use more extreme percentiles “methods of extremes” (2.5th to 97.5th) to make sure that everyone is protected (not just 95% of people).

19. Range of sizes versus adjustability Some equipment or products are designed to allow a variety of users to be able to access and use as they often include some adjustable features. Products might include car seats, office chairs, desk heights, footrests. Multivariate accommodation (fitting in several variables, for example, in a car you need to fit in terms of sitting height, leg room, arm reach, viewing angles, hip breadth, thigh length) means that accepting 5% being designed out for each important dimension is not viable, because different people will be designed out for each variable. People have different proportions. Those designed out because they are too tall may not be the same as those designed out because their arm reach is too short. T he range from 5th percentile female to 95th percentile male will accommodate 95% of a male and female population because of the overlap between female and male body dimensions for each dimension.

20. 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

21. Reach- Workspace envelope Reach is also known as 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.

22. Adjustability Certain products tend to be available in different sizes or with adjustability built in as there really is no ‘one size fits all’. 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. 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 provide the user with many adjustable features including: seat height and backs, leg room, seat belts, steering wheels, mirrors, headrest, etc.

23. Ergonomes In a number of the illustrations given in the last few slides there are representations of humans taken from an orthographic view that is to say a 2D front, side or plan elevation. These 2D scaled physical anthropometric model based on a specific percentile. human forms are called ergonomes . The ergonomes have been scaled from data taken from specific percentile ranges to form a standard human form. Plastic or card manikins can be used which are hinged at the major joints, to allow a variety of positions which allows a designer to check standing and seating positions. Ergonomes are used with drawings of the same scale as the model to consider the relationship between the size of an object and people. They are used with 2D drawings, mainly for orthographic drawings and also modelling to view field of reach, field of vision, etc. Topic 1.1

24. Manikins A manikin is an anatomical 3D model of the human body. A jointed model of the human body used by artists, especially to demonstrate the arrangement of drapery. Also called lay figure. They are useful for assessing the relationship of body parts to spatial arrangements represented by a 3D model, for example, a chair to a desk. Full scale manikins are generally more expensive than ergonomes and they give a better representation of the overall ergonomics in the design context (such as crash test dummies). Topic 1.1

25. Designing using Anthropometric data Which user population and percentile ranges would be required for the following products? Are all of the measurements necessary? Sitting height: Leg room: Arm reach: Viewing angles: Hip breadth: Thigh length: Childs Car Seat Office Chair

26. 1.2 Psychological factors 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 Essential Understanding: • 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 a breakdown in the human information processing system • User responses to environmental factors • How environmental factors induce different levels of alertness • The importance of optimizing environmental factors to maximize workplace performance • Assessing the impact of perception in relation to the accuracy and reliability of psychological factor data You as a designer: The analysis of the human information processing system requires you as a designer to critically analyse a range of causes and effects to identify where a potential breakdown could occur and the effect it may have.

27. Psychology in Human Factors 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. Since that time, human factors psychology has continued to grow and today plays an important role in many other fields, including computing, manufacturing, product design, engineering, military, and government industries.

28. Cognitive Psychology 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_publicaties/top10_-1/Top_10-1_Abstracts_en_Lijst_-_oud_van_IO_Campus/doc/Schiffersteinsplitmodality.pdf

29. Scale Design Context Nominal Ordinal Interval Ratio Data Car Design Small, medium, large, Sports, SUV cars Comfort rating of seats in car Speed Fuel Efficiency Example Categories of cars Use a rating scale of 1–10 to evaluate user responses. from 60-100 km/h Ratio between models 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 Designers need to use a variety of methods for collecting psychological data and these can be broken down into the four main scales used when collecting ergonomic data: Nominal, Ordinal, Interval and Ratio data scales Below is a table to show the relevance of using the different rating scales with the car as an example of a design context. Psychological factor data

30. Nominal Scale 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 have any value. The number serves only to identify the colour. Which iPhone 5C are people likely to buy according to http://www.mobilephones.com yellow is the least sold colour and blue is the most popular choice - regardless of internal storage capacity.

31. Ordinal Scale 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 burns.

32. 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. However, an interval scale does not have to have a true zero. Good examples of interval scales are the Decibel sound scale and the Fahrenheit and Celsius temperature scales. A temperature of "zero" does not mean that there is no temperature...it is just an arbitrary zero point.

33. 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 A. Unlike the interval scale, the ratio scale has a true zero value. Link to check for understanding of all scales http://psc.dss.ucdavis.edu/sommerb/sommerdemo/scaling/levels.htm

34. Nominal Scale Ordinal data scales Nominal means ‘by name’. Used in classification or division of objects into discrete groups. Each of which is identified with a name. The scale does not provide any measurement within or between the categories Deals with the order or position of items Words, letters, symbols or numbers arranged in a hierarchical order Quantitative assessment can not be made Methods of collecting Psychological factor data

35. Interval data scales Ratio data scales Organised into even divisions or intervals The intervals are of equal size. There is no zero 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. A ratio scale allows you to compare differences between numbers. Methods of collecting Psychological factor data

36. Human information processing systems 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 using a handphone to dial a number. 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 input sensory processes central processes motor processes output

37. Human information processing systems Scenario: Using a mobile handphone When using a mobile phone, the information flow diagram to make a telephone call input sensory processes central processes motor processes output Telephone number Eyes are used to read Brain processes number Nerve impulses to muscles Dial number with fingers

38. Human information processing systems Scenario: Driving a Car A car driver processes information from the road and the car and produces various control responses such as braking or changing gear input sensory processes central processes motor processes output Traffic lights at junction are on RED Eyes take information & send information to Brain Information needs to be stored temporarily (memory) in order for the brain to decide on what action is to be taken; before it sends the information to the motor process selects a response coded as a series of nerve impulses transmitted to the leg and foot muscles Driver presses the brake pedal with foot

39. Breakdown with the Human information processing systems It is worth investigating the effects and reasons for a breakdown in the human information processing system. The flow process may break down when the information inputs may be incompatible with the sensory receptors. At the central processing stage, the incoming information may be incorrect or no suitable responses to it are available. The motor output stage may be unable to perform the actions specified by the central processing unit. Some examples of how the flow process may break down are dependent on the following: Age, skills level, disability, infirmity or frailty Young children may not have the size, strength, fine motor control or skill to perform the tasks. Older people may not have the strength People with disabilities, such as arthritis or Parkinson's disease, may also not have the fine motor control required. A physical condition which can include: ALS: Amyotrophic lateral sclerosis, MS: Multiple Sclerosis, Arthritis, Partial paralysis, Parkinson’s disease, Repetitive Strain injury, Blindness, Hearing, Reduced sense of feeling input sensory processes central processes motor processes output

40. Methods of collecting psychological data A case study is an in-depth study of one person. In a case study, aspects of the subject's life and history is analysed to seek patterns and causes for behaviour. The hope is that learning gained from studying one case can be generalized to many others. Unfortunately, case studies tend to be highly subjective and it is difficult to generalise results to a larger population. For example how a particular teenager interacts with video game controls over a period of time. Naturalistic observation is a research method commonly used. This technique involves observing subjects in their natural environment. This type of research is often utilised in situations where conducting lab research is unrealistic, cost prohibitive or would unduly affect the subject's behaviour. For example how a particular fighter pilot reacts in a cockpit under stress. Naturalistic observation differs from structured observation in that it involves looking at a behaviour as it occurs in its natural setting with no attempts at intervention on the part of the researcher. Advantages of Naturalistic Observation It allows the researcher to directly observe the subject in a natural setting. It allows researchers to study things that cannot be manipulated in a lab due to ethical concerns. For example, while it would be unethical to study the effects of imprisonment by actually confining subjects, researchers can gather information by using naturalistic observation in real prison settings. It can help support the external validity of research. It is one thing to say that the findings of a lab study can be generalised and applied to a larger population, but quite another to actually observe those findings occurring in a natural setting. Disadvantages of Naturalistic Observation It can be difficult to determine the exact cause of a behaviour as the experimenter cannot control outside variables. People may behave differently when they know they are being watched. People may try to behave in a certain way in order to conform to what they think the researchers expects to see. Different observers may draw different conclusions from the same witnessed behaviour

41. Environmental factors Environmental factors play an important role in maximising workplace performance and reducing the possibilities of accidents. This table categorises them to include: Management Policies, safety education, decision centralization Physical environment Noise, temperature, pollutants, trip hazards, signage Equipment design Controls, visibility, hazards, warnings, safety guards The work/job itself Boredom and repetitiveness, mental and physical workload, musculoskeletal impacts such as force, pressure and repetition) Social and psychological environment Social group norms, morale The worker Personal ability, alertness, age, fatigue

42. Effect of environmental factors This picture shows a dirt path worn across the grass on a university campus. Notice how the path is in the most convenient place to walk relative to the crosswalk painted on the street and the dip in the curb. It looks like there should be a sidewalk here, but someone forgot to put it in. Instead of putting in a sidewalk, someone put in a sign to try to tell people not to walk on the grass. Here is a close-up picture of the "Keep off the grass" sign! Do you think this sign is really going to work? Design suggestion Take a hint from people's behavior. If they find it convenient to walk in a particular place, put in a sidewalk, not a barrier. This is an example of "natural" design. http://www.baddesigns.com/

43. The importance of controlling environmental factors to maximise workplace, performance includes the influence of the psychological human factors of noise and temperature such as shown here on the design of an open-plan office. Personal Factors such as clothing and metabolic heat also need to be considered. Effect of environmental factors These environmental factors must include consideration for sound-absorbing 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. Thermal comfort describes a person’s psychological state of mind and involves a range of environmental factors which contribute to thermal comfort in office and other working environments.: Air temperature (the heat radiating from the Sun, fires and other heat sources) Radiant temperature (the heat transfer from human body) Air velocity (the movement of air, still air makes people feel stuffy, moving air increases heat loss) Humidity

44. Effect of environmental factors- Excessive noise Excessive noise in the workplace can cause workers to lose their hearing and/or to suffer from tinnitus (permanent ringing in the ears). The level at which employers must provide hearing protection and hearing protection zones in, for example, the UK is now 85 decibels and the level at which employers must assess the risk to workers’ health and provide them with information and training is now 80 decibels.

45. Alertness Alertness has been recognized as a critical, yet often elusive, foundation for successful decision-making across a broad range of complex and dynamic systems including aviation , air traffic control , ship navigation health-care, emergency response and military command and control operations, and offshore oil and nuclear power plant management; to more ordinary but nevertheless complex tasks such as driving an automobile or bicycle . Alertness is the key term and means being aware of what is happening in the vicinity, in order to understand how information, events, and one's own actions will impact goals and objectives, both immediately and in the near future. One with an adept sense of situation awareness generally has a high degree of knowledge with respect to inputs and outputs of a system, i.e. an innate "feel" for situations, people, and events that play out due to variables the subject can control. Lacking or inadequate alertness has been identified as one of the primary factors in accidents attributed to human error . Human error come in several forms but two fundamental categories are slips and mistakes . Slips result from automatic behaviour, when subconscious actions that are intended to satisfy our goals get waylaid en route. Mistakes result from conscious deliberations. Thus, alertness is especially important in work domains where the information flow can be quite high and poor decisions may lead to serious consequences. Having complete, accurate and up-to-the-minute alertness is essential where technological and situational complexity on the human decision-maker is a concern.

46. Alertness 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 stripe 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. http://www.baddesigns.com/ Design suggestion When there is a strong likelihood of forgetting a critical step in a hazardous procedure, it would be better to have an automatic way of doing that step. For example, a better solution would be to have a sign or signal that automatically occurs when the slide is activated. This image shows that a key has to be placed in the door by the air crew in order to ensure the door has been secured properly and cannot be opened accidentally. Fatigue, stress, temperature and noise levels have a significant impact on alertness. Long repetitive task may often lead to a lack of concentration and errors/accidents may occur. Dangerous or very stressful situations can also affect people’s judgments.

47. Perception The human mind cannot effectively deal with chaos. The mind is programmed and designed to create order when confronted with many objects. The consequence of this is that human beings when using a product or service generally do not really see objects; they see classes, groups or patterns of controls and feedback. This interior seat adjustment control panel in a Mercedes-Benz car is an excellent example of natural mapping. The control is in the shape of the seat itself and the mapping is straightforward. Mercedes-Benz cars are obviously not everyday things for most people, but the principle could be applied to much more common objects. This natural mapping of seeing a pattern rather than a thing is called a “perception effect.” Assessing the impact of perception in relation to the accuracy and reliability of psychological factor data is important.

48. Human Error Human error has been seen as a key factor associated with almost every major accident, with catastrophic consequences to people, property and the environment. Accidents with major human contributions are not limited to any particular parts of the world, or any particular industry, and include the Bhopal chemical release (1984), the Chernobyl melt-down and radioactivity release (1986), the Piper Alpha platform explosion (1988) and the Kegworth air disaster (1989). The Bhopal disaster, also referred to as the Bhopal gas tragedy, was a gas leak incident in India, considered the world's worst industrial disaster. It occurred on the night of 2–3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh. Over 500,000 people were exposed to methyl isocyanate (MIC) gas and other chemicals. The toxic substance made its way in and around the shanty towns located near the plant. The Chernobyl disaster was the worst nuclear power plant accident in history in terms of cost and casualties, and is one of only two classified as a level 7 event (the maximum classification) on the International Nuclear Event Scale (the other being the Fukushima Daiichi nuclear disaster in 2011). The Kegworth air disaster occurred on 8 January 1989 when British Midland Flight 92, a Boeing 737-400, crashed onto the embankment of the M1 motorway near Kegworth, Leicestershire, UK. The aircraft was attempting to conduct an emergency landing at East Midlands Airport. Of the 126 people aboard, 47 died and 74, including seven members of the flight crew, sustained serious injuries.

49. 1.3 Physiological factors Essential Idea: Designers consider physiological factors to ensure products meet ergonomic needs. Designers study physical characteristics to optimize the user’s safety, health, comfort and performance. Concepts and principles: • Physiological factor data • Comfort and fatigue • Biomechanics Essential Understanding: • 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 You as a designer: Understanding complex biomechanics when designing products to enable full functionality of body parts can return independence and personal and social wellbeing to an individual.

50. Physiological factors Types of physiological factor data are available to designers and collected to optimize the user’s safety, health, comfort and performance. A recap on human factor design. It considers the: effectiveness (completeness and accuracy) efficiency (speed and effort) engagement (pleasantness and satisfaction) error tolerance (error prevention and error recovery) learnability (predictability and consistency) It also considers which activities can be carried out and how human values (for example, quality of life, improved safety, reduced fatigue and stress, increased comfort levels and job satisfaction) are enhanced. Physical limitations also need to be considered and these include: 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

51. Physical ergonomics Physical ergonomics is concerned with human anatomy, and some of the anthropometric, physiological and bio mechanical characteristics as they relate to physical activity. Physical ergonomic principles have been widely used in the design of both consumer and industrial products. Physical ergonomics is important in the medical field, particularly to those diagnosed with physiological ailments or disorders such as arthritis (both chronic and temporary) or carpal tunnel syndrome. Pressure that is insignificant or imperceptible to those unaffected by these disorders may be very painful, or render a device unusable, for those who are. Many ergonomically designed products are also used or recommended to treat or prevent such disorders, and to treat pressure-related chronic pain. Past examples include screwdriver handles made with serrations to improve finger grip, and use of soft thermoplastic elastomers to increase friction between the skin of the hand and the handle surface.

52. Physiological factors When users interact with products, they may put stress on their bodies. Comfort and fatigue are physiological factors that inform design decisions, and should be considered on how these can affect users.

53. Comfort Comfort is a physiological factors that inform design decisions and can affect users. What is Comfort? 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 is of primary concern to designers. It determines how effective a design is and how well a human can interact with a product. How comfortable to use something is to use is extremely important. If its comfortable the user will want to continue using it, if its not they won’t. The utility of an item is a good way to measure the quality of a 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 human-machine 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 lightweight and flimsy you will not feel that comfortable using it. The look, feel, use and durability of a product help you make a mental determination about a product or service. Basically it lets you evaluate the quality of the item and compare that to the cost. Better ergonomics mean better quality which means you will be more comfortable with the value of the item. Below is a great article explaining how Fastco ensure comfort on the new airbus http://www.fastcodesign.com/3028839/terminal-velocity/350-people-8-hours-airbus-tests-how-not-to-make-passengers-go-nuts?partner=newsletter http://www8.hp.com/us/en/hp-information/ergo/index.html#work-better http://www.apple.com/about/ergonomics/index.html

54. Comfort Comfort is a physiological factors that inform design decisions and can affect users.

55. Comfort

56. Fatigue Fatigue is the temporary diminishment of performance. Fatigue can be physical and/or mental. Fatigue can inform design decisions and can affect users.

57. Enhanced work environments Designing ergonomically enhanced work environments and products, has advantages for the employer and employee. Healthy Workforce: Instead of workers adjusting to standard tools and equipment, ergonomics promotes product designing based on human body structure and requirements. Therefore, these products drastically reduce the strain workers experience due to repetitive use of machines, computers, scanners, industrial apparatus and related instruments. Less strain equates to reduced instance of occupational illnesses and therefore healthier employees. Enhanced Productivity : A healthy workforce translates to enhanced productivity. Easy to use equipment keeps the work momentum going on for longer durations. Workers experience less fatigue and are happy to use tools designed especially for them. Reduced Number of Sick Days Reported: People with reduced instance of work associated ailments implies they take fewer days off due to sickness and work more number of days in a year. This means lesser number of workdays is lost. Savings : By using ergonomic workstations, employers save huge amounts of money otherwise spent in compensation claims, treatments and litigation. human model fatigue analysis programme:

58. Biomechanics in human factors Biomechanics in human factors includes the research and analysis of the mechanics (operation of our muscles, joints, tendons, etc.) of our human body. The importance of analysing the biomechanics in the use of a product of a given artifact is crucial to ensure the well-being of the user. Factors to consider include posture, muscle strength and age of the target user and how they interact with the product which might include the handle size, surface texture, and torque required.

59. Biomechanics in human factor design deals with four key criteria: Force Repetition Duration Posture Biomechanics in human factors Let’s analyse the biomechanics when considering the use of a wheelchair Force : Excessive impact jolts the user’s joints and causes their muscles to tense in response. Some wheelers snap their arms at the end of a push, which puts force on the shoulder joints. If the user is able to do a wheelie over a curb, they have to decide whether they land with impact, or allow themselves to go over the edge gently. Going over a significant bump at too great a speed in a powered wheelchair or scooter can result in unnecessary impact. Repetition : Pretty obvious one and we will consider the impact on a wheelchair user. How many pushes does it take them to travel a given distance? It is advised that it would be a better advantage to carry out coasting (which means keeping the tires inflated and the wheelchair well maintained) and consider going a little slower (it takes more pushes to go faster). Duration refers to continuous muscular effort. It does not have to be heavy lifting. Small exertions continuously held are as stressful to the human tissues as brief, heavy effort. Leaning on armrests – often because of a poor relationship to the seat and back – putting continuous load on shoulders is an example of doing "static" exertions. Poor posture is a duration overexertion. If the person tends to slump or lean forward, the trunk and neck and shoulder muscles have to do a lot of continuous work. The key here is movement and it is strongly advised not to be continually exerting muscles if active and changing the posture throughout the day. People often spend a lot of time leaning on armrests or a table exactly because they are not being supported with good posture in their chairs. This is a matter of seat angle and back angle, adjusting them according to the body shape and degree of upper body balance. Poor seating makes one slump, trying to get stable. The optimal posture is more upright, allowing the spine to act as main support as it is a structural column. Seat depth is involved here, too and if the seat is too short for the legs, then there is a loss of greater stability that comes with full contact between the seat and legs.

60. Biomechanics in human factors With biomechanics, measuring the amount of force put on the muscles and joints of people when working in different positions can be tested by determining which positions make use of an individual’s muscular strength. A muscle’s ability to perform is affected by the way it is used or another way to say it is the activity the muscle is performing. The activity can be either Static or Dynamic. Static - Holding one object or body part in one position for an extended period. eg. Standing or sitting in a parking booth or at a microscope. Think about how tiring you get when you sit or stand in one position for a long period of time. In an office it might be at the computer all day without a break, think about how tiring that feeling is. Or it could be standing in one position all day performing the same tasks or driving for several hours. Muscles fatigue faster when they are held in one position. Dynamic - An activity created by the rhythmic contraction and relaxation of the muscles. eg. Walking Dynamic work positions, that is positions that change, allow muscles to rest during the relaxation phase. The importance of biomechanics to the design of different products considering muscle strength, age, user interface and torque Factors affecting Muscle strength: Gender Age - - Greatest around 20’s - 5% less in 40’s - 20% less in 60’s Pain, Physical training schedule, Immobilization or bed bound

61. Biomechanics in human factors Use the examples below to explain the importance of biomechanical factors to making the design a success.

62. Legacy slides

63. Sliding calipers (or vernier callipers) or skinfold calipers This caliper works similar to those used in our workshops- vernier caliper. These torso calipers make a direct reading of the distance between the subject's back and the front of the subject's abdomen. Cloth tape Flexible cloth or ribbon tape measure which can be moulded round the body. Sitting height meter The Sitting Height Table has a standard type of ball-bearing mounted, counter-balanced head block, giving accurate and direct readings from 320 mm to 1090 mm. In addition it has a secondary carriage, fitted with an anti-reverse carriage lock, in order to compensate for upper leg variations: and an adjustable foot-rest in order to compensate for lower leg variations. Collecting Anthropometric Data The actual data is collected using a range of different tools, sliding calipers, skinfold calipers, fabric tapes and stadiometers. Topic 1.1

64. Collecting Anthropometric Data Task 4- You are going to collect some primary anthropometric data. You will be measuring and recording the sizes of students. You will need a lot of data, work in a team to collect these measurements. Agree on a simple measurement that you can take with a ruler or tape measure. Eg. circumference of the head, or fingertip to bottom of the palm. Agree on a simple measurement that the student should be able to tell you. Eg. shoe size. Record your findings. Use a tally chart or similar to record this data as accurately as you can. Your team needs to be able to easily put all the data together so work with the same system. Consider if you need any other information from the students? Once you have collated your information as a team, set the results out in a bar chart or line chart as shown below. Topic 1.1

65. Designing using Anthropometric data Step 1: Decide who you are designing for Anthropometry tables give measurements of different body parts for men and women, and split into different nationalities, and age groups, from babies to the elderly. So first of all you need to know exactly who you are designing for. The group of people you are designing for is called the user population . If you were designing an office chair, you would need to consider dimensions for adults of working age and not those for children or the elderly. If you were designing a product for the home, such as a kettle, your user group would include everyone except young children. Step 2: Decide which body measurements are relevant You need to know which parts of the body are relevant to your design. For example, if you were designing a mobile phone, you would need to consider the width and length of the hand, the size of the fingers, as well as grip diameter. Step 3: Decide whether you are designing for the 'average' or extremes Nobody is 'average' in all body dimensions. Someone might be say, of average height but have a longer than average hand length. You can measure your own height when you are standing up straight (without shoes!), and measure the length of your hand from your wrist to the tip of your middle finger. The variation in the size and shape of people also tells us that if you design to suit yourself, it will only be suitable for people who are the same size and shape as you, and you might 'design out' everyone else! Look up the 'average' heights and hand lengths for your age in the table below and compare your own measurements. Are you taller or shorter than average for your age group? Are your hands longer or shorter than average? All measurements are for British people and are in millimetres (ref: Bodyspace). Topic 1.1

66. Effect of environmental factors The problem The lids on oatmeal containers were recently redesigned. The new style lid fits down into the top of the oatmeal container. There's a lip all the way around the inside of the lid (arrow). The lip, which looks like it could work as a handle, affords sliding one's fingers underneath to pick up the oatmeal container. The other day I reached into the pantry to grab the oatmeal. I put my fingers under the lip of the lid using my thumb to hold the side on the container the lids on an oatmeal container. I got just a few steps from the pantry before the lid came off dumping oatmeal all over the floor! The problem is that it looks like you can pick up the container by the lid, but you can't. Maybe the purpose of this new lid is to get people to buy more oatmeal, since half of it ends up on the floor! The old-style lid doesn't look like you could use it as a handle to pick up the oatmeal container, so people probably aren't inclined try it. People are probably more apt to use two hands to pick up containers with these old-style lids. Design suggestion The lid on the new-style container should not look like it could work as a "handle" to pick up the container. This might be done by: Not making the center of the lid set down in the top of the container so deeply. Removing the "handle" from the inside of the lid by curving the lip outward rather than inward. Topic 1.2

67. Effect of environmental factors- Thermal comfort The thermal environment has to satisfy the majority of the people. Thermal comfort is not measured by air temperature, but by the number of people complaining of thermal discomfort. Thermal comfort can affect morale and productivity. In most countries there are legislative requirements for temperature in the workplace. Legislation sets minimum and maximum temperatures for different types of workplace, and workers have the right to refuse to work if such temperatures are not maintained. Thermal comfort describes a person’s psychological state of mind and involves a range of environmental factors. Legislation bodies use questionnaire or surveys to identify potential issues as part of a planned workplace inspection, such as: Do you find the atmosphere hot, cold, stuffy or draughty? When do you notice these conditions? What effect do these conditions have on your work? How do you deal with them? Topic 1.2

68. Effect of environmental factors Why might you have trouble with this faucet? The owner repeatedly find himself turning these cross-shaped handles the wrong way. So instead of turning the water off, he ends up turning it on full blast. Analyze this faucet and figure out the problem. The main problem is that the cold water handle opens clockwise, whereas the hot water handle opens counter-clockwise. Traditionally, faucets with these cross-shaped handles, both hot and cold, always open counter-clockwise. As the saying goes, "lefty loosely, right tightly". Like a screw, you turn left to loosen and right to tighten. Think of the number of things you use everyday, such as jars, bottles and caps of toothpaste tubes, which follow this same principle! Thus, the way the cold-water handle opens is unexpected and causes mistakes. Why is the faucet designed like this? During a trip to the local hardware store it was found that manufacturers have designed one basic faucet that is sold with two different handles: cross-shaped handles and lever handles, like the faucets pictured here. They probably do this to save money. Apparently, some people prefer the way the cross-shaped handles look and some prefer the lever handles. The lever handles, shown in this picture work well with the way the faucet opens. You expect the right lever handle to open clockwise and the left handle to open counter-clockwise (as shown). People expect familiar controls like cross-shaped faucet handles to work in a certain way (to open counter-clockwise). When they don't work in the expected way, people have problems. Manufacturers must consider people's expectations. Therefore, when the cross-handles are used, the faucet should be equipped with a cold water valve that opens counter-clockwise. When the lever handles are used, the cold water valve should open clockwise. http://www.baddesigns.com/ Topic 1.2

69. Psychological factor data - light 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 measurements, shades of grey work well. Shades of grey are easy to distinguish and have a natural ordering. Data visualization relies on vision, but vision is just one sense. Topic 1.2

70. Psychological factor data - smell 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 dimensional creations try to capture the changing smells of a place at a granular level. Of course, her process involves visualizing scent, but imagine how powerful those maps could be if she could capture that scent and expose users of her maps to them. Topic 1.2

71. Psychological factor data - sound Data in relation to Sound Hearing tests are normally delivered by through “audio boxes,” where an individual sits in the room with headphones on and the examiner plays distinct sounds for the listener. The individual will respond to whether or not he or she heard the sound, and the examiner makes a graph with the frequency (in Hz) on the x-axis and volume (in dB) on the y-axis. (Reference: http://www.who.int/occupational_health/publications/noise8.pdf ) How three-month-old babies recognise human voices and can work out when someone is sad http://www.dailymail.co.uk/sciencetech/article-2009940/How-month-old-babies-recognise-human-voices-work-sad.html Taste Topic 1.2

72. Psychological factor data - taste Data in relation to Taste Topic 1.2

73. Psychological factor data - temperature Data in relation to Temperature Topic 1.2

74. Psychological factor data- data Data in relation to Texture Topic 1.2

75. IB Design Technology Core Topic 1 Human factors and ergonomics

76. Topic 1: Human factors and ergonomics 1.1 Anthropometrics Anthropometric data: static and dynamic data, structural and functional data Primary data versus secondary data Percentiles and percentile ranges Range of sizes versus adjustability Clearance, reach and adjustability Collecting anthropometric data considering reliability and limitations Interpreting percentile tables for user populations Design contexts where different percentile ranges are used 1.2 Psychological factors Psychological factor data Human information processing systems Effect of environmental factors Alertness Perception 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 a breakdown in the human information processing system User responses to environmental factors How environmental factors induce different levels of alertness The importance of optimizing environmental factors to maximize workplace performance Assessing the impact of perception in relation to the accuracy and reliability of psychological factor data 1.3 Physiological factors Physiological factor data Comfort and fatigue Biomechanics 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

77. T1.1 Summary notes Define the term ‘ Human Factors ’ What are the advantages and disadvantages of collecting primary data versus secondary Anthropometric data? What are the aims of Human Factors? What tools can be used to collect Anthropometric Data? What is Ergonomics ? Percentiles and percentile ranges What do we mean by the term physical ergonomics ? Give an example. What do we mean when we discuss clearance in Human Factors? What do we mean by the term cognitive ergonomics ? Give an example. What do we mean when we discuss reach in Human Factors? What do we mean by the term organisational ergonomics ? Give an example. Why does a designer need to consider adjustability when designing seating? What is Anthropometric data ? Explain what is meant by the range of sizes versus adjustability Difference between Static and Dynamic Anthropometric data? Give some examples of products designed using Static or Dynamic data. What is an ergonome and when are they used? What are the advantages and disadvantages? Difference between Structural and functional Anthropometric data? What is a manikin ? What are the advantages and disadvantages?