Week 19 · learning day 1
Prototype purpose
Prototyping and Testing · 45–60 minutes
Today’s outcomes
- Explain prototype purpose in the context of prototyping and testing.
- Frame a product decision using the source outcome rather than intuition alone.
- Produce a reusable section of a prototype test card.
Source trace
W19-O01Explain prototypes and the advantages of using prototypes.
Core lesson
Make the choice inspectable
Prototype purpose matters when it changes a real allocation of attention, money, time, or delivery capacity. A prototype is a question made tangible at the cheapest useful fidelity.
Start by naming the decision and the uncertainty around it. Separate evidence from assumptions, compare at least one alternative, and state what would make you revise the choice.
The source outcome for today is: Explain prototypes and the advantages of using prototypes.
What decision will prototype purpose improve, what evidence is sufficient for that decision, and what is the cost of being wrong?
Worked example
Prototype purpose in practice
For a remote physiotherapy service, the product manager must frame a choice about prototype purpose. The team records the target user and outcome, the evidence currently available, the strongest alternative, and the next reversible test. The recommendation is written as a choice with a reason—not as a list of features.
Do the work · 20 minutes
Turn the idea into a decision
- Choose a product you know and write the specific decision that prototype purpose should support.
- List two pieces of evidence, two assumptions, and one credible alternative.
- Make a recommendation in three sentences and add one condition that would change it.
Save to your portfolio
A prototype test card — section: Prototype purpose
Knowledge check
Answer before opening
What is the decision at the centre of prototype purpose?
A good answer names an accountable choice, not merely an activity or output.
How should evidence and assumptions be separated?
Label observed facts, interpretations, and untested beliefs explicitly so the next learning step is visible.
What makes the recommendation revisable?
It includes a trigger, threshold, or new evidence that would justify changing course.
What should the portfolio artefact communicate?
The context, considered alternatives, chosen direction, rationale, evidence, and remaining risk.
Spaced review
Reconnect the learning
Reflection