Explicit engineering instruction
Engineering begins by defining what success means. Criteria are measures used to compare solutions; constraints are limits that acceptable solutions must satisfy.
A vague goal such as 'make it better' should become measurable targets such as mass, cost, efficiency, safety, or error rate.
The strongest design brief separates must-have constraints from preferences and identifies what evidence will test each claim.
Vocabulary: criterion; constraint; specification; requirement; metric.
Worked example
A bridge model may require mass under 100 g as a constraint while maximizing supported load as a criterion.
Guided question
Rewrite a vague design goal into one constraint and two measurable criteria.
Independent work
- Create a design brief for a supplied problem.
- Separate constraints from criteria.
- Assign units or scoring rules to each criterion.
Misconception check
A criterion is not automatically a constraint; preferences and hard limits play different roles.
Formative check
What makes a criterion measurable?
Reveal response
It has an observable or calculable metric with a defined scale or unit.
Mentor evidence conference
Ask Archaemenes to challenge criteria, weights, assumptions, and whether the evidence justifies the revision.
Teacher guidance
Foundation: Use a criteria/constraints organizer.
Core: Write measurable specifications.
Extended: Identify hidden stakeholder assumptions.