Defining a Design Problem
Aligned to 3-5-ETS1-1 — Next Generation Science Standards.
What this lesson teaches
Engineers start by naming the problem clearly. A good problem statement lists the criteria (what success looks like) and the constraints (limits on materials, time, or money) before any building begins.
Worked examples
Example 1
Your backpack strap keeps slipping off your shoulder. The criteria: it must stay put while you walk. The constraints: you can only use things from a junk drawer and finish in 20 minutes.
Example 2
Your bike chain keeps slipping off. Criteria: it stays on through a bumpy ride. Constraints: no new parts, fix it with tools you own.
Example 3
Write the problem as what must happen, not as the solution you already have in mind. 'Keep the chain on' leaves room for ideas; 'buy a chain guard' does not.
Practice questions
- Pick a small annoyance at home and write it as a clear problem to solve.
- List two criteria for success and two constraints for your problem.
- Explain why knowing the constraints before building saves time and materials.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Definir un Problema de Diseño
Los ingenieros empiezan por nombrar el problema con claridad. Un buen planteamiento del problema enumera los criterios (cómo se ve el éxito) y las restricciones (límites de materiales, tiempo o dinero) antes de empezar a construir.
Ejemplo 1: La correa de tu mochila se te resbala del hombro. Los criterios: debe quedarse en su lugar mientras caminas. Las restricciones: solo puedes usar cosas de un cajón de trastos y terminar en 20 minutos.
Ejemplo 2: La cadena de tu bici se sale todo el tiempo. Criterios: se queda puesta en un camino con baches. Restricciones: sin piezas nuevas, arréglala con las herramientas que tienes.
Ejemplo 3: Escribe el problema como lo que debe pasar, no como la solución que ya tienes en mente. 'Que la cadena no se salga' deja espacio para ideas; 'compra un cubrecadena' no.
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