Phase 2: Describing What You Want · 25 min · Any vibe coding tool

Plain English Specs That Work

The AI doesn't read your mind. It reads your words. Make them count.

Hiring signal: What changes when you use this: your first build attempt is close to right — which means you save 30-50% of your time on corrections.

What you will learn

Use the 5-part spec framework to write build descriptions
Understand the difference between specificity and verbosity
Recognize and avoid common spec mistakes
Write specs that produce close-to-right first attempts

Your Mission

Write a complete 5-part spec for a small app, build from it, and evaluate whether the spec produced a close-to-right first attempt. Output: spec_and_build.md.

You need: Any AI coding tool. A text editor.

Time: 30 minutes.

Step 1: Learn the 5-Part Spec Framework (5 min)

Every good spec has 5 parts:

1. What It Is — One sentence. "A single-page landing page for my freelance web design business."

2. Who It's For — Who will use this. "Potential clients who are small business owners looking for a web designer."

3. Features (What It Does) — List every feature explicitly. If you don't list it, the AI will guess.

Bad: "It should have a form"
Good: "Contact form with fields: name, email, project type (dropdown: Website, Landing Page, E-commerce, Other), message. On submit, show a success message."

4. Style (What It Looks Like) — Be specific. Colors, layout, mood.

Bad: "Make it look good"
Good: "Clean, modern, white background with navy blue (#1e3a5f) accents. Sans-serif font. Generous whitespace. Mobile-first."

5. Constraints (What You Don't Want) — Explicitly state what to exclude.

"No blog, no pricing table, no team page, no testimonials, no dark mode toggle. Single page only."

Specificity vs. verbosity
A good spec is specific, not verbose. "Tip buttons: 15%, 18%, 20%, 25% in a horizontal row of pills, selected one highlighted green (#10b981)" is specific. "The tip buttons should be nicely styled and easy to use with good colors and a modern look" is verbose but says nothing the AI can act on. Every sentence should tell the AI something it can implement. If a sentence doesn't change what the AI builds, delete it.

Unlock the full lesson

You've read the first 2 sections. The rest of this lesson covers Step 2: Write Your Spec (10 min), My Spec, Step 3: Build From It (10 min), Step 4: Evaluate (5 min), Evaluation, You're Done — plus a hands-on lab, quiz, and project artifact.

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