Investigating using secondary data (AQA GCSE Design and Technology): Revision Notes
Investigating using secondary data
Understanding secondary data in design
Secondary data investigation is a crucial part of the design process that helps us understand how products interact with their users. This information comes from research that has already been conducted by others, rather than collecting new data ourselves. By using this existing information, designers can make better decisions about how to create products that work well for their intended users.
Secondary data is particularly valuable in design because it saves time and resources while providing insights based on extensive research that would be expensive and time-consuming to conduct independently.
Ergonomics
Ergonomics focuses on the relationship between people and the products they use. The main goal is to understand how products can be designed to be more comfortable and efficient for users. This is essential because poorly designed products can cause discomfort, inefficiency, or even injury.
There are several key areas where ergonomic principles are applied:
Signs and visual communication need to be instantly recognisable so users can understand them quickly without confusion. This includes emergency signs, warning labels, and user interface elements.
Layout design considers how elements like keyboard layouts and fonts are standardised to make them easier to use. When users encounter familiar layouts, they can work more efficiently.
Strength requirements ensure that operating mechanisms are within the user's physical capabilities, helping to reduce the risk of accidents or strain injuries.
Good ergonomic design is often invisible to users - when a product feels natural and comfortable to use, it's usually because ergonomic principles have been carefully applied throughout the design process.
Anthropometrics
Anthropometrics is the scientific study of human body measurements and how these relate to product design. This field provides designers with statistical data about human dimensions, which is essential for creating products that fit and work well for their intended users.
The data used in anthropometrics comes from measuring large numbers of people to understand the range of human dimensions. These measurements include height, hand size, reach, and other physical characteristics.
This data is broken down by different groups such as gender, age, and ethnicity, because these groups often have significantly different ranges of measurements. Ignoring these differences can result in products that exclude entire user groups.
This information is particularly valuable when designing furniture, clothing, bicycles, and other products where fit and comfort are important factors.
Normal distribution and targeting users
When anthropometric data is collected and analysed, it typically follows a pattern called normal distribution. This creates a bell-shaped graph where most people fall near the middle (average), with fewer people at the extremes.
Understanding this distribution is crucial for designers because it helps them decide which users to target. The middle 90% of users (from the 5th to 95th percentile) represents the main target group, while the top and bottom 5% are considered extremes that would be very expensive to design for.
The 50th percentile represents the average user - this is where exactly half the population falls above and half falls below. This is often the starting point for many design decisions.
For example, when designing chair seat heights, the 50th percentile represents the average user, while the 5th and 95th percentiles represent the shortest and tallest users respectively. A fixed-height chair might be designed for the 50th percentile, while an adjustable chair could accommodate the full range from 5th to 95th percentile.
Strategies for targeting more customers
Since it's often impossible to create one product that fits all users perfectly, designers use several strategies to maximise the number of people who can use their products effectively:
Universal design approach aims to make one design suitable for as many users as possible. Cinema seats, for example, are designed to accommodate the maximum range of body sizes, ensuring that most people can sit comfortably.
Multiple size options involves creating the same product in different sizes to hit specific points on the distribution curve. Clothing is a perfect example of this approach, with different sizes targeting different user groups.
Adjustable products can be modified by users to fit their individual needs. Examples include adjustable car seats and rucksack straps that can be lengthened or shortened.
Accessory solutions provide additional components that can modify an original design for different users. Foam inserts for bicycle helmets allow the same helmet shell to fit different head sizes.
The choice of strategy depends on cost considerations, manufacturing complexity, and how critical precise fit is for the product's function and safety.
Practical applications
Understanding anthropometric data helps designers make informed decisions about product dimensions. For instance, when designing seating, knowing that adult male seat heights range from (5th percentile) to (95th percentile) helps determine whether to create a fixed or adjustable height product.
Sometimes designers need to consider extreme cases, such as knowing the 100th percentile data to understand maximum user requirements like weight capacity.
Practical Application: Office Chair Design
When designing an office chair, anthropometric data guides multiple decisions:
- Seat height range: 385mm-470mm to accommodate 5th-95th percentile users
- Seat depth: Based on thigh length measurements to ensure proper support
- Backrest height: Determined by torso measurements for lumbar support
- Armrest positioning: Set according to elbow height when seated
This data ensures the chair will be comfortable and functional for the vast majority of users.
Worked examples
When examining real products, we can see how anthropometric principles have influenced their design.
Worked Example: Hair Dryer Design
A hair dryer demonstrates several anthropometric considerations:
- Handle diameter: Sized to fit comfortably in the palm of the hand across different hand sizes
- Control placement: Positioned within easy thumb reach without requiring grip adjustment
- Weight distribution: Balanced to minimise strain during extended use
- Cord length: Provides sufficient reach for various user heights and bathroom layouts
These design decisions ensure the product is usable and comfortable for the target market.
Worked Example: Office Chair Ergonomics
Office chairs demonstrate multiple ergonomic features for extended workplace use:
- Adjustable seat height: Accommodates different leg lengths
- Lumbar support: Matches the natural curve of the spine
- Armrest positioning: Reduces shoulder and neck strain
- Seat depth and width: Provides proper weight distribution
- Swivel base: Allows easy movement without straining
These features work together to create a comfortable working environment that reduces fatigue and injury risk.
Key Points to Remember:
- Secondary data provides valuable information about how products interact with users without conducting new research
- Ergonomics focuses on making products comfortable and efficient by understanding the relationship between people and products
- Anthropometrics uses statistical data about human body measurements to inform design decisions
- Normal distribution shows that most users fall in the middle range, with few at the extremes
- Targeting strategies include universal design, multiple sizes, adjustable features, and accessories to maximise product usability
- The 5th to 95th percentile range typically represents the main target user group for most products