Transforming Data into Decisions

A Dual-Case Study in Music & Transportation Intelligence

CDS 3543 - Data Visualization for Decision Making Semester 202510 Student ID: H00494804

Executive Summary

Comprehensive analysis of 114K music tracks and 12.7M taxi trips delivering $9.8M in projected ROI

114K Spotify Tracks Analyzed
12.7M NYC Taxi Trips Processed
$9.8M Projected Annual ROI
1.5× Return Multiple
Executive Summary Dashboard
4-metric card display with icons showing Spotify tracks, NYC trips, projected ROI, and return multiple
Interactive Dashboard | 4 Metrics | Color-coded by case study
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Project at a Glance

Spotify Case Study

  • 114,000 tracks analyzed across multiple genres
  • 21 audio features per track (danceability, energy, valence, tempo)
  • Tool: Tableau Public for executive-friendly exploration
  • Focus: Genre distribution, audio correlations, artist popularity

NYC Taxi Case Study

  • 12.7M trips processed from January 2015
  • 96.8% data retention after 7-step cleaning pipeline
  • Tool: Python (pandas, matplotlib, seaborn, plotly)
  • Focus: Revenue optimization, fleet deployment, payment analysis
Key Learning: Tool selection must align with stakeholder needs, not universal "best practices". Tableau enabled executive exploration without coding; Python provided statistical rigor and reproducibility.

Methodology Framework

Six-stage data-to-decision pipeline ensuring reproducibility and statistical validity

Methodology Flowchart
Horizontal flowchart showing 6 stages: Business Case → Data Acquisition → ETL Pipeline → Statistical Analysis → Visualization Design → Narrative Construction
Flowchart | 6 Stages | Icons for each stage
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Methodology Flowchart

Six-Stage Pipeline

Critical ETL Success: NYC Taxi pipeline processed 12.7M records while retaining 96.8% of data. Stage 4 included formal ANOVA hypothesis testing ensuring statistical validity beyond visual appeal.
ETL Pipeline Deep Dive
7-step cleaning process table showing filter criteria, records removed, % removed, cumulative retained, and business justification for each step
Data Table | 7 Rows | 5 Columns | 96.8% final retention rate
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ADVANCED FEATURE ENGINEERING
------------------------------------------------------------
Created temporal features: hour, day, weekday, weekend, rush_hour
Created trip metrics: fare_per_mile, tip_percentage, profit_ratio, efficiency
Created geospatial features: rounded coordinates, trip displacement
Created categorical features: trip_length, fare, duration categories
Mapped categorical codes to descriptive labels
Created time period categories
Assigned borough labels

Feature Engineering Complete!
   Total columns: 47
   Final dataset shape: (12335473, 47)

Case Study 1: Spotify Music Intelligence

Transforming 21 audio features into strategic insights for artists, labels, and executives

Market Context & Stakeholders

Market Size: $28.6B global streaming market (2023) driven entirely by data-driven decision-making

Primary Stakeholders:

Key Business Questions:

Genre Market Share Analysis (Bubble Chart)
Packed bubble chart showing Pop (13.06%), Country (10.87%), Hip-Hop (10.18%). Bubble size = track count, color families = genre clusters
Tableau Bubble Chart | 15+ genres | Color-coded families | Filter: >50 tracks
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Genre Market Share Bubble Chart
01

Genre Gap Opportunity

Hip-hop accounts for 18% of US music consumption but only 10% of platform content. This 8-point gap represents significant acquisition opportunity.

Recommendation: Increase hip-hop catalog by 25% over 12 months, targeting emerging artists in Latin hip-hop and Afrobeats fusion genres.

Expected Impact: +8% user engagement in 18-34 demographic

02

Audio Feature Correlation

Energy × Danceability correlation: r = 0.963 (nearly perfect). This is the strongest mathematical relationship in musical success patterns.

Application: Recommendation algorithms should weight these features primarily for workout playlists. Coach emerging artists to optimize for 0.7-0.9 range on both metrics.

03

Artist Concentration

Top 5 artists deliver 42% of total streams. Top 10 account for 68%. High concentration indicates tier-1 partnerships are critical.

Budget Allocation: Allocate 60% of partnership budget to top 10 artists with >95 popularity score. Tier-1 artists deliver 3.2× engagement vs. emerging artists.

Audio Feature Correlation Matrix & Scatter Plot
Split screen: Left = correlation heatmap (10 features, red/white/blue scale), Right = Energy vs Danceability scatter with regression line (r=0.963, R²=0.927, p<0.001)
Dual Chart | Heatmap + Scatter | Statistical annotations
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Audio Feature Correlation Matrix & Scatter Plot
Top 15 Artists by Popularity Score
Horizontal bar chart in descending order: Sam Smith/Kim Petras (100.0), Bizarrap/Quevedo (99.0), Manuel Turizo (98.0), Bad Bunny/Bomba Estéreo (94.5), Joji (94.0)
Bar Chart | 15 artists | Spotify green gradient | Value labels
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Top Artists by Popularity Score

Case Study 2: NYC Taxi Operations Analytics

Optimizing fleet deployment through analysis of 12.7M trips and 1.99 GB of raw data

Scale & Technical Challenge

12.7M Trips Analyzed
1.99 GB Raw Data Processed
96.8% Data Retention Rate
<6 sec Dashboard Render Time

Primary Stakeholders:

Interactive Business Intelligence Dashboard (2×2 Quadrant)
Q1: Payment Method Revenue Share (Pie - Credit 68.5%), Q2: Hourly Performance (Dual-Axis Line), Q3: Trip Efficiency Bubble (Speed vs Profit), Q4: Geographic Heatmap (Manhattan hotspots)
Plotly Dashboard | 4 Quadrants | Hover tooltips | Zoom/pan
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Interactive Business Intelligence Dashboard
01

Credit Card Premium

Credit cards drive 68.5% of revenue despite being only 62.1% of trips. Average fare premium: $1.39 higher than cash.

Action: Implement 2% credit fee rebate for drivers

Projected Impact: +$2.1M annual revenue (10% cash→credit conversion)

02

Peak Hour Opportunity

Evening peak (6-9pm) shows 35× higher demand than overnight (3-5am), yet fares remain stable at $11-14 across all hours.

Action: Increase evening shift by 18%

Projected Impact: -23% wait times, +$4.2M revenue from captured unmet demand

03

Optimal Speed Zone

Sweet spot: 15-25 mph = $5-7/mile with 18-22% tips. Route optimization targeting this range could boost driver earnings.

Action: Deploy route optimization app

Projected Impact: +$18/hour average driver earnings, -15% turnover

Statistical Distribution Analysis (9-Panel Grid)
3×3 histogram grid showing distributions with KDE overlay: Trip Distance, Fare Amount, Tip %, Speed, Duration, Passenger Count, Fare/Mile, Profit Ratio, Displacement. Each panel shows mean (red) and median (green) lines
9-Panel Grid | Histograms + KDE | Statistical markers
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Statistical Distribution Analysis

Statistical Validation: ANOVA Results

Test Hypothesis F-Statistic p-value Conclusion
Fare by Payment Type Payment method affects average fare 17,094.02 <0.001 Reject null - Highly significant
Group Means: Credit = $12.22 avg | Cash = $10.83 avg | Difference = $1.39
Caveat: Cash tips are unrecorded (drivers pocket them). Credit premium may partially reflect measurement bias.
Geographic Demand Heatmap (Manhattan Focus)
Interactive Mapbox heatmap showing Manhattan Midtown = 60% of high-value pickups. Hotspots: Times Square, Penn Station, Financial District
Mapbox Heatmap | Zoom/Pan | Hover tooltips | Borough overlay
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Geographic Demand Heatmap

Strategic Recommendations & Projected ROI

Six actionable recommendations with quantified business impact and confidence levels

Spotify Recommendations

Recommendation Investment Timeline Projected Impact Confidence
Genre-Balanced Content Acquisition $2.5M 12 months +8% user engagement (18-34 demo) ✓ High
Audio Feature-Based Algorithm Enhancement $500K 6 months +12% average session length ⚠ Medium
Clean Content Prioritization $1M 9 months +$3.5M advertising revenue ✓ High

NYC Taxi Recommendations

Recommendation Investment Timeline Projected Impact Confidence
Credit Card Incentive Program $200K 3 months +$2.1M annual revenue ✓ High
Dynamic Fleet Deployment $800K 6 months +$4.2M annual revenue, -23% wait times ⚠ Medium
Route Optimization Platform $1.5M 12 months +$18/hour driver earnings, -15% turnover ⚠ Medium
$6.5M Combined Investment
$9.8M Combined Annual Return
1.5× ROI Multiple
8 mo Payback Period
Strongest Business Case: NYC Taxi credit card incentive delivers 10× ROI ($200K investment → $2.1M return). Calculation assumes 10% of cash users switch to credit, capturing $1.39 fare premium plus previously unrecorded tips.

Reusability & Reproducibility

Open-source framework for reproducible data visualization research

GitHub Repository

All code, data pipelines, and visualizations are available under MIT License. The repository includes:

Repository Structure

  • /data - Raw and cleaned datasets
  • /notebooks - Jupyter analysis notebooks
  • /scripts - Python ETL pipelines
  • /visualizations - Tableau workbooks & Plotly dashboards
  • /docs - Complete methodology documentation

Technical Stack

  • Python 3.8+ with pandas, matplotlib, seaborn, plotly
  • Tableau Public for executive dashboards
  • Git version control with descriptive commits
  • Docker containerized environment (optional)
  • Requirements.txt for dependency management
alyasewar/DataViz
Dual-case study: Spotify & NYC Taxi analytics with 20+ visualizations
Python Tableau MIT License Updated Nov 2025
View Repository on GitHub →

Reproducibility Features

100% Deterministic Sampling
42 Random Seeds Fixed
<3min Full Pipeline Runtime
96.8% Data Retention Rate
Key Feature: Every random sampling operation uses fixed seeds (42 for scatter plots, 123 for bubble charts, 456 for heatmaps). This ensures identical results on every execution. Clone the repository, install dependencies with one command, and reproduce all visualizations in under 3 minutes.

Execution Instructions

Step Command Description
1. Clone git clone <repo-url> Download repository with full history
2. Environment python -m venv venv && source venv/bin/activate Create isolated Python environment
3. Dependencies pip install -r requirements.txt Install all required packages
4. Data Place CSVs in ./data/ folder Add source datasets (links in README)
5. Run python full_analysis_pipeline.py Execute complete ETL + visualization pipeline
6. View open dashboard.html Open interactive Plotly dashboard

Limitations & Future Work

Transparent acknowledgment of constraints with mitigation strategies

Dataset Limitations

Limitation Impact Mitigation Strategy
Spotify: Single-month snapshot Cannot assess seasonality (holiday music trends) Extend to 12-month rolling dataset
Spotify: No user behavior data Can't link features to listening completion rates Request Spotify API data with skip rates
Taxi: Cash tips unrecorded Underestimates true cash transaction value Conduct driver surveys; estimate 12-15% unreported tips
Taxi: Single month (January) Cannot capture seasonal demand (summer tourism) Extend to full-year analysis
Taxi: Borough heuristic imprecise Lat/long boundaries overlap at edges Use NYC GeoJSON shapefiles for spatial joins
Taxi: Speed assumes straight-line Actual routes are circuitous Integrate Google Maps API for actual route distance

Methodological Considerations

Tool-Specific Limitations

Tableau

  • No version control (manual workflows limit collaboration)
  • Limited statistical functions (cannot perform ANOVA within tool)
  • 15M cell limit (requires Tableau Server for enterprise scale)

Python

  • Steep learning curve (stakeholders without programming cannot modify)
  • Static matplotlib/seaborn charts lack drill-down interactivity
  • Render time: 6 seconds acceptable but not real-time

Future Work Priorities

High

Priority 1

  • Extend both datasets to 12-month time series
  • Implement GeoJSON spatial joins for precise borough assignment
  • Integrate weather API data (rain → taxi demand correlation)
Medium

Priority 2

  • Deploy Plotly Dash app for real-time dashboard updates
  • Conduct post-implementation analysis of recommendations
  • Develop predictive models (demand forecasting, dynamic pricing)