Unit 3 · Programming 2 · Lesson 3.25 · Practice PT

Written Responses, Timed

The last step of the dress rehearsal: answer the Create PT’s written-response questions about your own program, under time pressure — then peer-score with the real guidelines. The grade is gentle; the calibration is the point.

Big Idea 3 — Algorithms & ProgrammingTimed · then peer-scored
Check the current CED for exact wording. The written-response prompts have been reworded before. These reflect the recent structure; use your exam year’s official prompts and scoring guidelines when you practice.
1

Where We Are

People→ Bits→ Programs→ Internet→ Security→ Big Data→ Impact

Last day of Programs and of Unit 3. Your program and PPR are done (3.22–3.24). Now you do the part that actually earns most of the writing points: explaining your own code precisely, on the clock. Every “how my conditional works” paragraph since 2.17 was training for this.

2

The Hook

You wrote the code. Now prove you understand it. Plenty of students submit working programs and still lose writing points — because they describe what the code looks like instead of what it does, or they forget to name the parameter, the selection, the iteration.

The written responses are open-PPR: you’re explaining code that’s right in front of you. The whole skill is precision — using the exact terms for the exact lines. Do it timed today so it’s automatic in May.

3

The Two Kinds of Response

The written responses come down to two jobs. Answer both about your own program and PPR.

Response A — Purpose & the procedure

Prompt (in short). Describe the overall purpose of your program, and explain how your student-developed procedure works — including what its parameter does and the algorithm inside it.

Write it now for your program. Three to five sentences. Then open the checklist.

Full-credit Response A does all of this:

□ States the program’s purpose — what problem it solves or what it’s for.

□ Names the procedure and its parameter, and says how the parameter affects the result.

□ Describes the algorithm inside using the words iteration and selection for the actual loop and if.

□ Says what the procedure returns and how the program uses it.

Response B — Data & development

Prompt (in short). Explain how your list (or collection) manages complexity, and describe how you developed and tested the program — including a bug or difficulty and how you resolved it.

Write it now. Three to five sentences. Then open the checklist.

Full-credit Response B does all of this:

□ Explains how the list manages complexity — why the program would be harder or worse without it (imagine 30 separate variables).

□ Describes a real step in development — something you built, tested, then improved.

□ Names a specific bug or difficulty and how you found and fixed it — precisely, not “it didn’t work so I fixed it.”

□ Uses correct terms and refuses to over-claim — the recurring skill all year.

4

Score It — Yours, Then a Partner’s

After the timed write, score against the guidelines — first your own, then swap with a partner. Check every point the response truly earns. Be strict; that’s the gift.

Check each point the response genuinely earns.

An unchecked box is a specific, fixable gap — the most useful feedback you can get. On a first attempt, three or four of six is normal; the calibration is what you keep.

5

Impact Check

Explaining your work is half of every technical job

Code that no one can explain is code no one can trust, maintain, or build on. Writing a clear, precise account of what you built and why — naming the parts, owning the bugs, not overselling — is a huge part of real engineering: pull requests, design docs, incident write-ups. The PT’s written responses train exactly that, and it will serve you far past this exam.

6

Connections

Trained since 2.17 — every “how my conditional works” and 3.15 procedure sentence was building to this.
Uses 3.22–3.24 — you’re explaining the exact program and PPR you just built.
Closes Unit 3 — the biggest unit ends with the skill the whole course points at: build something, then explain it precisely.
Returns for real — these are the actual exam written responses. You’ve now done the whole PT once, gently graded, before it counts.
← 3.22–3.24 Build Days