A good exploratory data analysis report usually follows this workflow:
Understand the Objective
Start by asking:
- What question am I trying to answer?
- What business problem am I solving?
Example:
Understand sales performance and identify trends, patterns and opportunities for improvement
Understand the Dataset
Describe what the data contains.
Example:
- Orders
- Customers
- Products
- Sales
- Discounts
- Profit
- Dates
Identify
- Number of rows and columns
- Types of variables:
- Numerical (Sales, Profit, Quantity)
- Categorical (Category, Region, Customer Segment)
- Dates (Order Date, Ship Date)
Assess Data Quality
Check for potential issues:
- Missing values
- Duplicate records
- Incorrect data types
- Impossible values
- Outliers
Document what you would do to clean the data, even if you don’t actually modify it.
Generate Descriptive Statistics
For important numerical variables:
- Mean
- Median
- Standard Deviation
- Minimum
- Maximum
Ask
- What is a typical sale?
- How much variability exists?
- Are there extreme values?
Explore Relationships
Use visualizations to answer questions.
Bar Charts
Compare categories using Bar Charts.
Questions
- Which categories sell the most?
- Which product has the best margins?
Line Charts
Analyze changes over time using Line Charts.
Questions
- Are sales increasing/decreasing?
- Is there seasonality?
- Are there unusual spikes?
Histograms
Study data distribution using Histograms.
Questions
- Are sales concentrated in a certain range?
- Are there outliers?
- Is the distribution skewed?
Interpret Findings
Most important step.
Don’t just say:
“Sales reached 500000”.
Explain instead:
“Sales peaked in November and December, suggesting seasonal demand that could be leveraged through targeted marketing campaigns.”
Always move from:
Example
Observation
- High discounts often produce negative profits
Possible Explanation
- Some product are being discounted too aggressively
Business implication
- The company should review its discount policies to prevent selling at a loss
Summary Key Insights
A good report usually ends with 3-5 major findings.
Example
- Most daily sales are relatively small, with a few exceptionally high-sales days.
- Sales exhibit seasonal peaks during certain months.
- A small number of products generate a large share of revenue.
- Large discounts are associated with negative profits.
- Sales performance differs across categories and regions.
Provide Recommendations
Translate findings into actions.
Example
- Investigate causes of high-sales periods and replicate them.
- Monitor discount strategies.
- Focus marketing on top-performing categories.
- Analyze underperforming products and regions.
Report Structure
- Introduction: Objective of the analysis
- Dataset Description: columns and data types
- Data Quality Assessment: Missing values, duplicates, assumptions
- Descriptive Statistics: Mean, Median, Std Dev
- Visual Analysis
- Bar Chart
- Line Chart
- Histogram
- Key Findings: Patterns, trends, outliers
- Business Implications and Recommendations
- Conclusion: main takeaways and next steps