Inclusive design.
Requirements for product design and development · Technical principles
Revision notes
How to consider aesthetics, ergonomics and anthropometrics when designing products (A-level only)
Aesthetics
Aesthetics refers to the visual appeal of a product, such as shape/form, size, proportion, colour and texture.
• Design writer Donald Norman says ‘products and systems which make you feel good are easier to deal with, and produce more harmonious results’.
• Balancing aesthetics and function is central to the commercial success of a product.
Shape and form
• Shape is the 2D profile, and form is the 3D physical manifestation, of a product.
• Design movements such as Art Deco and modernism developed producible and functional designs that employed primarily geometric shapes and forms.
• Tangential lines and curves result in minimal designs with pleasing, smooth surfaces.
• This approach also improves the aerodynamic performance of designs when appropriate.
Symmetry and asymmetry
• Symmetrical handheld products offer inclusivity for both left- and right-handed users.
• Symmetry gives visual balance, whereas asymmetry can add interest and focus to designs.
Proportion
• This is the relationship between the dimensions of an object, such as width and height.
• In this case it is the overall proportion of an object, but key features, controls or elements within a design can be proportionally laid out.
• Proportion significantly affects aesthetics, and the ‘golden ratio’ (1:1.6) is often used.
• This ratio results in rectangles with very pleasing proportions to the human eye.
• The ‘golden ratio’ has been used in architecture, art and design for hundreds of years.
Anthropomorphism
• This is the use of recognisably human characteristics within design.
• Examples include Alessandro Mendini’s Anna G corkscrew and the 1915 Coca-Cola bottle.
• It provides emotional, often humorous connection to products, sometimes unintentionally.
Colour and texture
• Colour is an important element in the aesthetic appeal of product designs.
• Complementary colours (opposite sides of the colour wheel) are sometimes combined.
• Analogous colours (next to each other on the colour wheel) are chosen for some situations.
Symbols and ideograms
• These are instructive symbols independent of language knowledge.
• The diversity of populations makes their use increasingly important.
• Standardisation of symbols is important and helps promote inclusivity for children.
• Intuitive use of products is helped by colour associations such as:
○ red = stop, danger, heat, warning
○ green = go, environmentally friendly
○ blue = cold
○ yellow/black combination = danger warning.
Ergonomics (human factors)
• This is defined as the scientific study of people and their working conditions.
• Interaction with products through all senses needs to be considered to avoid discomfort and stress.
• A useful exercise is to study a range of pairs of scissors for different purposes and analyse the reasons for the differences in design.
• Ergonomics factors to consider:
○ the anthropometric data range of potential users
○ the full range of abilities of possible users concerning all senses
○ the movements and forces required when using the product
○ the shape and form of parts touched by users
○ the selection of materials
○ the selection of suitable colour schemes
○ the use of appropriate symbols.
• A car dashboard is a good example of a situation with wide-ranging ergonomic requirements:
○ it must allow the driver to focus on the road and also communicate vital information
○ the refill fuel warning, for example, might employ audible and visual stimuli.
Anthropometrics
Anthropometrics is the measurements of the human body in the context of product design.
• It helps designers to take into consideration the wide range of sizes and abilities that exists.
• Measurement data include height, weight, shoe size, arm length and grip strength.
• The graphical representation of data can help to show the range of measurements more clearly.
• The extremes of measurements often rule out inclusivity, usually affecting the top and bottom 5 per cent.
• Figure 22.9 shows a typical distribution graph based on a sample of results.
• Consider which percentile you would design for in a range of situations such as:
○ guard mesh spacing for a cooling fan (1st percentile child data would minimise safety compromises)
○ door opening height (95th percentile male height is approximately 1.85 m, but door openings are normally 1.98 m to accommodate a larger range and allow for the dynamics of movement)
○ car seat adjustment (5th percentile female to 95th percentile male)
○ worktop height (50th percentile would allow the widest range of people to reach).
• Notice that it isn’t always the 5th to 95th percentile figure that is used, as each situation needs an independent assessment, particularly where safety is a prime consideration.
• Office chair design is highly dependent on anthropometric data:
○ adjustable heights and angles accommodate a range of users
○ function is a high priority with its form being dictated by the need for comfort.
Exam tip
Don’t be simplistic in your responses to questions on anthropometrics – for example, ‘Products must be designed for the average size person’ or ‘designers must use the 5th to 95th percentile’. Write about the choice of specific data required for situations such as those mentioned in this chapter and also make reference to consideration of male, female and child data, as well as variations that may exist in overseas markets.
Typical mistake
Don’t concentrate only on anthropometrics when answering questions requiring an explanation of the term ergonomics. This is an important element, but you must also include a wider range of product features such as the type of grip, tactile recognition of controls, use of symbols, colour and sound, etc.
Inclusive design (REVISED)
This is a key part of user-centred design (UCD), facilitating maximum accessibility of products.
• Inclusive design aims to meet the needs of the widest possible range of people who might interact with the product in question. This includes groups such as the elderly, people with disabilities and children.
• Empathy with the target user is a key part of design inclusively for a range of abilities.
• Empathic design involves the designer analysing tasks while emulating user restrictions.
• Ford Focus designers wore a ‘third age suit’ (Figure 22.10) to experience the problems of less mobile motorists. The suit restricts joint movement, reduces the ability to grip and simulates visual impairment.
• Inclusive design of hand tools avoids problems such as undue stress on joints and slow working.
• Small, intricate movements such as using pencils and scalpels require a precision grip. Precision grip involves the thumb and index finger, and is usually between 8 and 16 mm diameter.
• Large forces require a power grip, where the hand wraps around a handle. Power grip for tools like screwdrivers and hammers requires a diameter of 30–50 mm.
• Indented finger grips should be avoided to reduce discomfort for small or large hands.
• Gentle curves, with appropriate texture, offer multiple gripping positions for the user.
Exam practice from my notes
13 Explain how a product may be designed to ensure inclusivity for a wide range of users. You should refer to specific design examples in your response. [9]
Inclusive design aims to make products accessible and comfortable for the widest possible range of users without the need for adaptation. Designers often use anthropometric data, such as the 5th to 95th percentile, so products accommodate different body sizes and physical abilities. For example, adjustable office chairs allow users to alter seat height, lumbar support and armrest position to suit different body types and improve ergonomics.
Products should also be intuitive and simple to use so users of different ages and technical abilities can understand them easily. For instance, smartphones use recognised icons and gestures so most users can navigate the interface without training. Large touchscreens and clear symbols improve accessibility for visually impaired or elderly users.
Many products include adjustable or customisable settings to improve inclusivity. Cars often feature adjustable steering wheels, seat memory settings and voice controls, allowing a wider range of users to drive comfortably and safely. Voice assistants such as Siri or Alexa also support users with limited mobility or visual impairments.
Designers may include textured surfaces or over-moulded grips to improve handling for users with weaker grip strength. Kitchen utensils such as Oxo Good Grips products use soft ergonomic handles that are easier to hold for elderly users or people with arthritis.
Colour contrast, font size and audio feedback can also improve accessibility. Public ticket machines often include high-contrast screens, multiple language options and audio guidance to support users with visual impairments or language barriers.
By considering ergonomics, accessibility, adjustability and intuitive interaction, designers can ensure products are usable by the largest possible audience.
ANTHROPROMETICS SUCH AS 5TH-95TH PERCENTILE TO ACCOMODATE FOR INDIVIDUALS OF ALL SIZE RANGES, ALLOWS FOR COMFORT AND EASY HANDLING OF PRODUCTS FOR PEOPLE IN ALL SIZE RANGES, EG ERGONOMIC CHAIRS WHICH CAN HEIGHT ADJUST AND MAKE ARMREST POSITION TO SUIT DIFFERENT BODY TYPES
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