C04 → C05 — Choose, then Detail

The Hamilton and Alexandra College · Year 12 · 2026

C04 and C05 sit back-to-back in the SAT and share the word design, so they're easy to blur. The distinction is simple once you see it: C04 decides which idea; C05 specifies that idea precisely enough to build.

The one-sentence rule

Criterion	In one sentence	The question it answers
C04 — Generating Design Ideas & Evaluation Criteria	Explore several rough design ideas, then use evaluation criteria to choose one	"Which design should proceed — and why?"
C05 — Producing Detailed Designs	Take the chosen idea and detail it until someone else could build it	"Exactly how is this built — every screen, field and step?"

The shift is breadth → depth: C04 is divergent (many options, then a decision); C05 is convergent (one option, fully specified).

One picture

C04 fans out into options and funnels in to a decision. C05 takes that single decision and fans it back out — but this time into detail, not alternatives.

flowchart LR
    I1["Idea A"] --> M{{"Evaluation matrix<br/>C04 · choose which"}}
    I2["Idea B"] --> M
    I3["Idea C"] --> M
    M ==>|"the chosen design"| D["Detailed design<br/>C05"]
    D --> T1["Mock-ups"]
    D --> T2["Data dictionary"]
    D --> T3["IPO charts"]
    D --> T4["Pseudocode"]
    D --> T5["Object descriptions"]

Side-by-side

	C04	C05
What you produce	Several rough ideas + an evaluation matrix	One detailed design of the chosen idea
Mindset	Explore, then decide	Commit, then detail
Key tools	Mood board, brainstorm, mind map, annotated sketches	Mock-ups, data dictionary, IPO charts, pseudocode, object descriptions
Output's job	Justify a choice	Be buildable
Leans on	Your SRS (C03) and design brief	Your C04 decision

The trap

C05 is not "make the C04 sketch look nicer." A rough idea becomes a detailed design when another person could build from it without asking you what you meant — exact data types in the data dictionary, real logic in the pseudocode, every control annotated on the mock-up. That buildable precision is the whole point of C05.

Tip

Architect's analogy: C04 is sketching three concepts and arguing for one. C05 is drawing the construction blueprints for the concept that won. You can't blueprint what you haven't chosen — so C05 depends on the C04 decision.

Check Your Understanding

In one phrase, what does C04 decide that C05 then assumes?

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Which design idea proceeds. C05 details that already-chosen idea — it doesn't re-open the choice.

Breadth or depth — which word fits C04, and which fits C05?

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C04 = breadth (several ideas, then choose). C05 = depth (one idea, fully specified).

A student repolishes the colours and fonts of their C04 sketch and submits it as their detailed design. What's missing?

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Buildable detail — data dictionary, IPO/pseudocode logic, annotated controls. "Looks nicer" is not "detailed enough for someone else to build."