🏆 Tiêu chuẩn — Code Review, Dashboard QA & Peer Review

Các tiêu chuẩn giúp bạn review code đúng cách, QA dashboard trước khi present, và peer review hiệu quả — 3 quality gates cho capstone project.

Tổng quan tiêu chuẩn buổi 19

Buổi 19 chuyển từ Code (analysis) → Dashboard → Executive Summary. Mỗi giai đoạn cần quality control riêng:

1. Code Review Standards — Review Jupyter Notebook: structure, reproducibility, documentation
2. Dashboard QA Checklist — Kiểm tra dashboard trước khi publish: accuracy, design, functionality
3. Peer Review Framework — Quy trình review đồng nghiệp: structured feedback, scoring, iteration

📋 Danh sách tiêu chuẩn liên quan

#	Tiêu chuẩn	Nguồn / Tham khảo	Áp dụng cho Buổi 19
1	Code Review Standards	Google Engineering Practices / PEP 8 / Jupyter Best Practices	Review Jupyter Notebook cho analysis quality
2	Dashboard QA Checklist	IBCS (International Business Communication Standards) / Stephen Few	QA dashboard trước khi present
3	Peer Review Framework	Agile Code Review / Design Critique guidelines	Structured peer review process

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1️⃣ Code Review Standards — Jupyter Notebook

Giới thiệu

Code Review — quy trình kiểm tra code của người khác (hoặc chính mình) để đảm bảo chất lượng, reproducibility, và readability. Trong DA, code review quan trọng vì: sai code = sai insight = sai quyết định business.

Theo Google Engineering Practices, code review kiểm tra 4 khía cạnh:

Khía cạnh	Câu hỏi	Ví dụ trong DA
Correctness	Code có chạy đúng không?	Merge data đúng key? Filter đúng condition?
Clarity	Người khác đọc hiểu không?	Variable names, comments, section headers
Consistency	Style nhất quán không?	PEP 8, naming convention, formatting
Completeness	Có thiếu gì không?	Edge cases, null handling, documentation

Notebook Structure Checklist

✅ STRUCTURE
├── Title & Author (Markdown cell đầu tiên)
├── Table of Contents
├── 1. Setup & Import Libraries
│   ├── All imports ở đầu file
│   └── Version info (pandas, sklearn, etc.)
├── 2. Load Data
│   ├── File path rõ ràng
│   └── df.shape, df.head(), df.info()
├── 3. Data Cleaning
│   ├── Missing values handled
│   ├── Duplicates checked
│   └── Data types corrected
├── 4. Analysis Sections (per business question)
│   ├── Markdown header: Question
│   ├── Code cells: Analysis
│   ├── Visualization
│   └── Finding Box: What → So What → Now What
├── 5. Summary of Findings
└── 6. References / Data Sources

Code Quality Rules

Rule	Bad ❌	Good ✅
Variable names	df2, x, temp	df_cleaned, churn_rate, monthly_revenue
Comments	Không comment	# Filter churned users in last 30 days
Magic numbers	df[df['age'] > 25]	MIN_AGE = 25; df[df['age'] > MIN_AGE]
Imports	Import giữa notebook	Tất cả imports ở cell đầu tiên
Output	Print tất cả mọi thứ	Print summary, hide intermediate steps
Charts	Không title, không label	Title, axis labels, legend, source
Cell order	Cells chạy lộn xộn, skip cells	Run All → no errors, sequential

Reproducibility Checklist

REPRODUCIBILITY — "Người khác chạy lại được không?"
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

✅ Random seed set: np.random.seed(42)
✅ File paths relative, not absolute: 'data/file.csv' (not 'C:\Users\...')
✅ Dependencies listed: requirements.txt hoặc comment
✅ Kernel → Restart & Run All → no errors
✅ Data source documented: file name, date, origin
✅ No hardcoded values that change: use variables
✅ Output cells saved: charts visible without re-running

Self-Review Template

Trước khi submit notebook, tự check:

#	Check	Pass?
1	Markdown cells giải thích mỗi section?	☐
2	Variable names descriptive?	☐
3	No unused code cells?	☐
4	All charts have title + labels?	☐
5	Findings documented (What/So What/Now What)?	☐
6	Kernel → Restart & Run All → no errors?	☐
7	No sensitive data (passwords, API keys)?	☐
8	Summary section at the end?	☐

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2️⃣ Dashboard QA Checklist — Trước khi publish

Giới thiệu

Dashboard QA — quy trình kiểm tra chất lượng dashboard trước khi gửi cho stakeholders. Theo IBCS (International Business Communication Standards), dashboard cần đạt 3 tiêu chí: accurate, clear, và actionable.

Dưới đây là checklist QA chia theo 5 categories:

Data Accuracy

DATA ACCURACY — "Số có đúng không?"
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

✅ Cross-check KPI cards với source data
   → Total Revenue trên dashboard = SUM(Revenue) trong dataset?
✅ Filters: khi filter 1 segment → tất cả charts update đúng
✅ Grand total = sum of parts (sanity check)
✅ Date range correct — dashboard shows đúng period
✅ No double counting — JOIN logic đúng
✅ Null/blank handling — nulls không bị ẩn hoặc tính sai
✅ Year-over-Year calculation — compare đúng period

Visual Design

VISUAL DESIGN — "Nhìn có dễ hiểu không?"
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

✅ Visual hierarchy: KPI cards → Charts → Details (top → bottom)
✅ Font sizes: Title (18-20pt) > Chart title (12-14pt) > Labels (10-12pt)
✅ Color palette: max 5 colors, consistent across pages
✅ Same entity = same color across all charts
✅ White space: charts not cramped, room to breathe
✅ Alignment: charts aligned on grid
✅ Chart types appropriate:
   - Trend → Line chart
   - Comparison → Bar chart
   - Composition → Stacked bar / Donut
   - Correlation → Scatter plot
   - Distribution → Histogram / Box plot

Chart-Specific QA

Chart Element	Checklist
Title	Descriptive, includes time period: "Revenue by Product — FY2025"
Axes	Labeled with units (VND, %, count). Y-axis starts at 0 (bar charts)
Legend	Positioned consistently (top-right hoặc bottom). Readable
Data labels	Only on key data points — not every bar
Gridlines	Light/subtle or removed. Not distracting
Tooltips	Show useful context on hover: value, %, period
Sort order	Meaningful: descending by value, chronological, alphabetical
Number format	Consistent: 1.2M or 1,200,000 — pick one style

Functionality & Interactivity

FUNCTIONALITY — "Interactive features hoạt động đúng?"
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

✅ Slicer/Filter: Date, Region, Category — filter across all visuals
✅ Cross-filtering: click on bar → other charts update correctly
✅ Drill-down: Year → Quarter → Month (nếu applicable)
✅ Reset: có button/option reset về default view
✅ Navigation: page tabs clear, named descriptively
✅ Mobile view: dashboard readable on tablet (nếu deploy online)
✅ Performance: dashboard loads trong < 5 giây

Content & Insight

CONTENT — "Dashboard này có GIÁ TRỊ không?"
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

✅ Mỗi page answer ít nhất 1 business question
✅ KPI cards có context: vs target, vs previous period, trend arrow
✅ At least 1 annotation/callout highlight key insight
✅ Recommendations page/section — không chỉ show data
✅ Dashboard title + subtitle + date range + data source
✅ "So what?" test — cho người khác xem 10 giây, họ biết insight chính?

QA Scoring Matrix

Category	Weight	Score (1-5)	Weighted
Data Accuracy	30%
Visual Design	25%
Chart Quality	20%
Functionality	15%
Content & Insight	10%
Total	100%		/5.0

Pass threshold: ≥ 3.5/5.0

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3️⃣ Peer Review Framework — Review đồng nghiệp hiệu quả

Giới thiệu

Peer Review — quy trình để đồng nghiệp (hoặc bạn cùng lớp) review output của bạn, đưa feedback, và bạn cải thiện. Peer review không phải "chấm điểm" — mà là collaborative quality improvement.

Theo Agile methodology, peer review hiệu quả cần:

Nguyên tắc	Mô tả
Be specific	"Chart 2 thiếu y-axis label" thay vì "charts chưa tốt"
Be kind	Feedback về work, không phải về person
Be constructive	Mỗi criticism đi kèm 1 suggestion
Be timely	Review SỚM — feedback ngày 1 quý hơn feedback ngày cuối

Peer Review Process

flowchart LR
    A["1️⃣ Prepare<br/>Builder self-review<br/>trước peer session"] --> B["2️⃣ Present<br/>3 min walk-through<br/>no defending"]
    B --> C["3️⃣ Review<br/>Reviewers fill form<br/>5 min"]
    C --> D["4️⃣ Discuss<br/>Clarify feedback<br/>5 min"]
    D --> E["5️⃣ Iterate<br/>Fix top 3 issues<br/>15-30 min"]

Review Roles

Role	Responsibility	Do	Don't
Builder	Present work, listen to feedback	Take notes, ask clarifying questions	Defend every choice, argue
Reviewer	Give structured feedback	Use template, be specific + constructive	Be vague, criticize person
Facilitator	Keep time, ensure balanced discussion	Ensure all reviewers speak	Let 1 person dominate

Peer Review Form

┌──────────────────────────────────────────────────────────────┐
│  📋 PEER REVIEW FORM                                          │
│                                                               │
│  Builder: ________________  Reviewer: ________________       │
│  Date: ________________    Project: ________________          │
│                                                               │
│  ━━━━━━━━━ NOTEBOOK ━━━━━━━━━                                │
│  [ ] Code runs without errors?              (1-5): ___       │
│  [ ] Structure clear (sections, headers)?    (1-5): ___       │
│  [ ] Findings documented?                    (1-5): ___       │
│  Comment: _______________________________________________     │
│                                                               │
│  ━━━━━━━━━ DASHBOARD ━━━━━━━━━                               │
│  [ ] Answers business question?              (1-5): ___       │
│  [ ] Visual hierarchy clear?                 (1-5): ___       │
│  [ ] Data appears accurate?                  (1-5): ___       │
│  [ ] Interactivity works?                    (1-5): ___       │
│  Comment: _______________________________________________     │
│                                                               │
│  ━━━━━━━━━ EXECUTIVE SUMMARY ━━━━━━━━━                       │
│  [ ] 5 findings clear?                       (1-5): ___       │
│  [ ] What/So What/Now What structure?        (1-5): ___       │
│  [ ] Recommendations actionable?             (1-5): ___       │
│  Comment: _______________________________________________     │
│                                                               │
│  ━━━━━━━━━ OVERALL ━━━━━━━━━                                 │
│  🌟 What works well:                                          │
│  ___________________________________________________________  │
│  ___________________________________________________________  │
│                                                               │
│  🔧 Top 3 improvements:                                      │
│  1. ________________________________________________________  │
│  2. ________________________________________________________  │
│  3. ________________________________________________________  │
│                                                               │
│  Overall Score (1-5): ___                                     │
└──────────────────────────────────────────────────────────────┘

Feedback Quality Guide

Level	Example (Bad → Good)
❌ Vague	"Dashboard chưa tốt"
⚠️ Better	"Dashboard thiếu KPI cards"
✅ Best	"Page 1 thiếu KPI cards ở top — thêm Revenue, Orders, AOV, Churn Rate với YoY comparison sẽ giúp viewer nắm context ngay"

Level	Example (Bad → Good)
❌ Only negative	"Chart sai, color xấu, font nhỏ"
✅ Balanced	"Trend chart insight hay! Suggestions: enlarge font to 12pt, use consistent blue palette, add annotation for Q3 dip"

Common Review Findings

#	Finding	Frequency	Fix Time
1	Missing axis labels	Very common	2 min
2	Inconsistent colors across pages	Common	5 min
3	KPI cards without comparison period	Common	5 min
4	Findings not documented in notebook	Common	15 min
5	Dashboard doesn't answer stated question	Occasional	30 min
6	Chart type inappropriate (pie for 10+ categories)	Occasional	10 min
7	Code not reproducible (hardcoded paths, no seed)	Occasional	10 min
8	Executive summary too vague	Common	20 min

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📋 Tổng hợp — Quality Gates cho Capstone

flowchart LR
    A["📓 Notebook<br/>Code Review<br/>Standards"] --> B["📊 Dashboard<br/>QA Checklist"]
    B --> C["👥 Peer Review<br/>Framework"]
    C --> D["📝 Executive<br/>Summary<br/>Review"]
    D --> E["✅ Ready to<br/>Present<br/>(Buổi 20)"]

Gate	Standard	Pass Criteria
Gate 1: Code	Code Review Standards	Restart & Run All = no errors. Findings documented
Gate 2: Dashboard	Dashboard QA Checklist	QA Score ≥ 3.5/5. Data verified. Interactivity works
Gate 3: Peer Review	Peer Review Framework	≥ 2 reviewers. Top 3 issues fixed. Overall ≥ 3/5
Gate 4: Summary	What/So What/Now What	5 findings. 3 recommendations with impact. 1-2 pages

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🔗 Liên kết

• 📘 Buổi 19: Lý thuyết
• 🛠 Workshop: Analysis Sprint
• 🎮 Game: Dashboard Sprint
• 📝 Blog: Sprint & Scope Creep
• 🧠 Case Study: Capstone Analysis