Ergonomics: fit a range of users
Введено| English | Значение |
|---|---|
| anthropometry/ˈænθrəpəmətri/ | антропометрия |
| ergonomics/ˌɜːɡəˈnɒmɪks/ | эргономика |
What would explain this observation?
- A handle sized for the average hand can exclude many intended users. Design decisions need a user range, task and context rather than one average.
Build the model
- Anthropometry 人体测量 measures body dimensions; ergonomics 人体工学 considers interactions between people, tasks and products.
- A percentile locates a value within a specified distribution.
- Choosing a lower or upper percentile depends on whether the dimension concerns reach, clearance or another function.
- Adjustable design may accommodate a broader range than a single fixed dimension.
- anthropometry: Measurement of human body dimensions for a specified population and method.
- ergonomics: Study of interactions between people, tasks and systems to inform design.
Which decision is most defensible when a fixed control is unreachable for some intended users?
Сложность 1/5 · 100 монет + небольшой бонус за первое выполнение сегодня
If some intended users cannot reach the control, the design fails them; testing a closer or adjustable position against the specified user range addresses the failure. Designing to the maximum reach or the mean still excludes users.
Match each technical term to its precise meaning.
Сложность 2/5 · 140 монет + небольшой бонус за первое выполнение сегодня
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- A clearance dimension often needs to consider larger relevant body dimensions, while reach can require smaller relevant dimensions.
- Neither principle automatically selects a universal percentile.
- The measured population, posture, clothing, capability and task determine relevance.
- Consider physical, perceptual and cognitive demands together rather than assuming body size explains every usability issue.
In the lab: Define a consenting user group and task. Use attributed data or anonymous teacher-approved measurements, record measurement posture and units, and test safe low-fidelity models before construction. Include users whose access needs differ. Set measurable acceptance criteria and retain qualitative feedback about grip, visibility and comprehension alongside dimensions.
Which two habits make the investigation or model in this case more defensible?
Сложность 2/5 · 140 монет + небольшой бонус за первое выполнение сегодня
Stating the conditions and assumptions lets others repeat the work exactly, and recording the supporting evidence lets them check the conclusion. Hiding disagreeing results removes the evidence that could challenge a wrong conclusion, and one measurement can never establish a wider claim.
Work from known quantities
- Known: sorted fictional reach measurements are 40, 42, 43, 45, 46, 47, 49, 51, 53 and 56 cm.
- Under a stated nearest-rank classroom convention, the 10th percentile uses rank ceil(0.10×10)=1, giving 40 cm; the 90th uses rank 9, giving 53 cm.
- A 53 cm control distance is beyond the recorded reach of eight users.
- The small fictional sample does not define a product standard.
Your turn: A stated nearest-rank method uses ceil(p×n). For p=0.90 and n=20, find the rank.
A stated nearest-rank method uses ceil(p×n). For p=0.90 and n=20, find the rank.
Сложность 2/5 · 140 монет + небольшой бонус за первое выполнение сегодня
The result is 18 rank. Known: nearest-rank convention rank = ceil(p x n); p = 0.90, n = 20. Rank = ceil(0.90 x 20) = ceil(18) = 18. The 18th value in the sorted list is the stated 90th percentile.
Check the conclusion and its limits
- Percentile methods differ, especially for small samples.
- A percentile is not a percentage of a body dimension.
- An average dimension and a successful test by one user do not establish accessible design.
Not true: A product dimension based on the mean automatically accommodates every intended user. Half of all users are above or below the mean, so a mean-based dimension excludes a large share by construction. Accommodation is judged across a range - often 5th to 95th percentile - not at the average.
- Anthropometry measures body dimensions; ergonomics considers interactions between people, tasks and products.
- A clearance dimension often needs to consider larger relevant body dimensions, while reach can require smaller relevant dimensions.
- Watch for: percentile methods differ, especially for small samples.
Write from rank 12
- A nearest-rank method uses the ceiling of percentile times sample size.
- The percentile is 0.80 and there are 15 sorted fictional measurements.
A product dimension based on the mean automatically accommodates every intended user.
Сложность 1/5 · 100 монет + небольшой бонус за первое выполнение сегодня
Half of all users are above or below the mean, so a mean-based dimension excludes a large share by construction. Accommodation is judged across a range - often 5th to 95th percentile - not at the average.
Measurement of human body dimensions for a specified population and method: write the technical term.
Сложность 1/5 · 100 монет + небольшой бонус за первое выполнение сегодня
anthropometry means Measurement of human body dimensions for a specified population and method.
Under the lesson's nearest-rank method, the percentile is 0.80 and the sorted sample has 15 measurements. What rank is used, and why is that rank not a percentage of a hand length?
Nearest rank takes the ceiling of percentile times sample size. Accommodation is judged across a range, not at the mean.
Which rank does this nearest-rank method use?
Сложность 1/5 · 100 монет + небольшой бонус за первое выполнение сегодня
0.80 times 15 is 12. The percentile locates a rank in the sorted list. It does not scale a hand length.