Defining a Problem
Aligned to 3-5-ETS1-1 — Next Generation Science Standards.
What this lesson teaches
Engineers start by clearly stating the problem they want to solve. They list what a good solution must do, called the criteria, and the limits they must work within, called the constraints, like the materials, time, or money they have.
Worked examples
Example 1
You want to keep an ice cube from melting for one hour. Your criteria is to slow the melting, and your constraints are that you can only use paper, tape, and one small box.
Example 2
You want a bird feeder squirrels cannot raid. Criteria: birds still reach the seed. Constraints: under $10 and it must hang from an existing hook.
Example 3
A problem with no constraints is not really defined. 'Make it better' cannot be tested; 'hold 2 pounds for 5 minutes' can.
Practice questions
- Think of a problem in your day. What would a good solution need to do?
- Write down one criterion (a goal) and one constraint (a limit) for building a bird feeder.
- Explain why knowing your constraints before you start building can help you succeed.
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
Los ingenieros empiezan por describir con claridad el problema que quieren resolver. Enumeran lo que una buena solución debe lograr, llamado criterios, y los límites dentro de los que deben trabajar, llamados restricciones, como los materiales, el tiempo o el dinero que tienen.
Ejemplo 1: Quieres evitar que un cubo de hielo se derrita durante una hora. Tu criterio es hacer que se derrita más lento, y tus restricciones son que solo puedes usar papel, cinta y una cajita.
Ejemplo 2: Quieres un comedero para aves que las ardillas no puedan saquear. Criterios: las aves sí alcanzan la semilla. Restricciones: menos de $10 y debe colgar de un gancho que ya existe.
Ejemplo 3: Un problema sin restricciones no está realmente definido. 'Hazlo mejor' no se puede probar; 'que sostenga 2 libras por 5 minutos' sí.
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