Lesson ProgressPhase 2 of 6
Phase 2Introduction
Introduction: Data Cleaning and Analysis
Data cleaning patterns, Excel tool locations, common failure modes
Phase 2: Tool Anatomy
Data Cleaning Tools and Patterns
Master the Excel tools that transform raw POS data into analysis-ready format.
The Data Cleaning Workflow
- Inspect: Open the raw file, check for obvious issues, count rows
- Clean Text: TRIM spaces, PROPER case for consistency
- Fix Formats: Text-to-Columns for dates, remove currency symbols
- Remove Duplicates: Delete repeated transactions
- Handle Missing: Fill, delete, or flag empty cells
- Validate: Spot-check calculations, flag outliers
- Document: Record what you changed and why
Tool Locations in Excel
Home Tab → Editing
- Find & Select → Go To Special
Data Tab
- Text to Columns (split columns)
- Remove Duplicates
- Filter (show/hide rows)
- Sort (A-Z, filters)
Formulas Tab
- TRIM(text)
- PROPER(text)
- CLEAN(text)
Analysis Tools
- Data Analysis → Descriptive Statistics
- Conditional Formatting → Highlight Cells
Common Failure Modes
❌ Skipping the Documentation
Always record what you changed. Investors ask "what did you do to this data?"
❌ Cleaning in the Wrong Order
Dates first, then duplicates, then text cleanup. Wrong order wastes time.
❌ Not Checking After Cleaning
Always spot-check totals before and after. A 10% row reduction matters.
Data Cleaning Vocabulary
Complete each sentence with the correct term.
Attempts: 0Score: 0%
📝 Fill in the Blanks
Complete each sentence by typing the missing word or phrase
📚 Word Bank
Available answers