---
title: "Designing for the People Who Use It"
description: "Use measured body data and user research to choose product sizes, reach distances and control requirements. Consider people with limited sight, hearing or movement, and test whether the design works f"
canonical: https://lightmysky.com/learn/design-and-technology/designing-for-the-people-who-use-it-mt_QPznzhuBNI
source: https://lightmysky.com/learn/design-and-technology/designing-for-the-people-who-use-it-mt_QPznzhuBNI.md
retrieved: 2026-11-12
---

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# Designing for the People Who Use It

Use measured body data and user research to choose product sizes, reach distances and control requirements. Consider people with limited sight, hearing or movement, and test whether the design works for its intended users.

Subject: Design & Technology · Area: Designing & Making · Ages 14 to 16
Page: https://lightmysky.com/learn/design-and-technology/designing-for-the-people-who-use-it-mt_QPznzhuBNI

## Ready when they can

- Explain why one average body measurement does not show the range of users or prove that a product will fit them
- Name two body measurements that inform product dimensions, such as hand breadth for handle length or seated lower-leg length for seat height
- Redesign one feature of a product so it works one-handed or without sight
- Explain how observing a task and asking users about it can provide complementary evidence, including actions they did not mention

## Lesson: Design for real bodies

Your brief names the people and tasks a product is for. One average body measurement does not show the range of those users. A product may fit people on either side of the average if it allows enough space or adjustment. Use measured ranges and fit tests to choose one size, several sizes or adjustment.

Hand breadth helps set handle length. Seated lower-leg length helps choose a seat height that supports the feet. Reach helps position controls. Body measurements inform product dimensions; they are not automatically the final dimensions. Clothing, movement, clearance and the task also matter.

*(drawing: Measurements guide a size choice. Testing checks whether it works during use.)*

Match signals to the person and task. Someone may miss a sound-only alert. A changing light or suitable vibration can provide another channel. A raised symbol identifies a control by touch; it does not announce completion. Several channels can help more users, but cannot guarantee access for everyone.

One-handed use needs reachable controls that one hand can operate. Limited hand strength may call for low-force controls and a stable product. For a ticket-machine user with limited strength and sight, try reachable low-force controls, tactile markings and audio guidance. Keep readable visual information too. Test the whole task with the intended user; button size alone does not establish access.

Ask users about their needs and, with their agreement, observe the task. Grip changes or workarounds may not appear in an interview. Ask what those actions mean before deciding they show a problem. Record both reported experience and observed actions in the brief, then test proposed changes.

**Recap.** Use body data to choose sizes and controls. Match access features to the task. Ask users, observe with their agreement and test the design.

*Original lesson, questions and flashcards written for this dataset about body measurements, accessible controls and user research.*

## Practice

8 questions on this page, each with its working shown.

## Needs first

- [Design briefs and better products](https://lightmysky.com/learn/design-and-technology/design-briefs-and-better-products-mt_QeNClHE0EG)

## Optional connections

- [Design That Changed the World](https://lightmysky.com/learn/design-and-technology/design-that-changed-the-world-mt_6PWs6Qp8V6)

## Opens up

- [The Whole Life of a Product](https://lightmysky.com/learn/design-and-technology/the-whole-life-of-a-product-mt_hyBZiDvDoX)