--- license: apache-2.0 task_categories: - graph-ml tags: - horology size_categories: - 100K Detailed Table of Contents * Summary * Key Statistics * Primary Use Cases * Dataset Description * Data Structure * Features * Network Properties * Processing Parameters * Technical Details * Power Analysis * Implementation Details * Network Architecture * Embedding Dimensions * Network Parameters * Condition Scoring * Exploratory Data Analysis * Brand Distribution * Feature Correlations * Market Structure Visualizations * UMAP Analysis * t-SNE Visualization * PCA Analysis * Network Visualizations * Ethics and Limitations * Data Collection and Privacy * Known Biases * Usage Guidelines * License * Usage * Required Files * Loading the Dataset * Code Examples --- ## Summary This dataset transforms traditional watch market data into a Graph Neural Network (GNN) structure, specifically designed to capture the complex dynamics of the pre-owned luxury watch market. It addresses three key market characteristics that traditional recommendation systems often miss: - **Condition-Based Value Dynamics**: Captures how a watch's condition influences its market position and value relative to other timepieces - **Temporal Price Behaviors**: Models non-linear price patterns where certain watches appreciate while others depreciate - **Inter-Model Relationships**: Maps complex value relationships between different models that transcend traditional brand hierarchies ### Key Statistics - Total Watches: 284,491 - Total Brands: 28 - Price Range: $50 - $3.2M - Year Range: 1559-2024 ### Primary Use Cases - Advanced watch recommendation systems - Market positioning analysis - Value relationship modeling - Temporal trend analysis ## Dataset Description ### Data Structure The dataset is structured as a PyTorch Geometric Data object with three main components: - Node features tensor (watch attributes) - Edge index matrix (watch connections) - Edge attributes (similarity weights) ### Features Key features include: - **Brand Embeddings**: 128-dimensional vectors capturing brand identity and market position - **Material Embeddings**: 64-dimensional vectors for material types and values - **Movement Embeddings**: 64-dimensional vectors representing technical hierarchies - **Temporal Features**: 32-dimensional cyclical embeddings for year and seasonal patterns - **Condition Scores**: Standardized scale (0.5-1.0) based on watch condition - **Price Features**: Log-transformed and normalized across market segments - **Physical Attributes**: Standardized measurements in millimeters ### Network Properties - **Node Connections**: 3-5 edges per watch - **Similarity Threshold**: 70% minimum similarity for edge creation - **Edge Weights**: Based on multiple similarity factors: - Price (50% influence) - Brand similarity - Material type - Temporal proximity - Condition score ### Processing Parameters - Batch Size: 50 watches per chunk - Processing Window: 1000 watches - Edge Generation Batch: 32 watches - Network Architecture: Combined GCN and GAT layers with 4 attention heads ## Technical Details ### Power Analysis Minimum sample requirements based on statistical analysis: - Basic Network: 10,671 nodes (95% confidence, 3% margin) - GNN Requirements: 14,400 samples (feature space dimensionality) - Brand Coverage: 768 watches per brand - Price Segments: 4,320 watches per segment Current dataset (284,491 watches) exceeds requirements with: - 5,000+ samples per major brand - 50,000+ samples per price segment - Sufficient network density ### Implementation Details #### Network Architecture - 3 GNN layers with residual connections - 64 hidden channels - 20% dropout rate - 4 attention heads - Learning rate: 0.001 #### Embedding Dimensions - Brand: 128 - Material: 64 - Movement: 64 - Temporal: 32 #### Network Parameters - Connections per watch: 3-5 - Similarity threshold: 70% - Batch size: 50 watches - Processing window: 1000 watches #### Condition Scoring - New: 1.0 - Unworn: 0.95 - Very Good: 0.8 - Good: 0.7 - Fair: 0.5 ## Exploratory Data Analysis **NOTE:** Only certain selected visualizations have been mentioned here, to see all the visualizations that have been explored in high-quality interactive graphs, please visit this site: [Watch Market Analysis Report](https://incomparable-torrone-ccda90.netlify.app/) ### Brand Distribution ![Brand Distribution Treemap](https://raw.githubusercontent.com/calicartels/watch-market-gnn-code/main/images/2.png) The treemap visualization provides a hierarchical view of market presence: - Rolex dominates with the highest representation, reflecting its market leadership - Omega and Seiko follow as major players, indicating a strong market presence - Distribution reveals clear tiers in the luxury watch market - Brand representation correlates with market positioning and availability ### Feature Correlations ![Feature Correlation Matrix](https://raw.githubusercontent.com/calicartels/watch-market-gnn-code/main/images/3.png) The correlation matrix reveals important market dynamics: - **Size vs. Year**: Positive correlation indicating a trend toward larger case sizes in modern watches - **Price vs. Size**: Moderate correlation showing larger watches generally command higher prices - **Price vs. Year**: Notably low correlation, demonstrating that vintage watches maintain value - Each feature contributes unique information, validated by the lack of strong correlations across all variables ### Market Structure Visualizations #### UMAP Analysis ![UMAP Visualization](https://raw.githubusercontent.com/calicartels/watch-market-gnn-code/main/images/4.png) The UMAP visualization unveils complex market positioning dynamics: - Rolex maintains a dominant central position around coordinates (0, -5), showing unparalleled brand cohesion - Omega and Breitling cluster in the left segment, indicating strategic market alignment - Seiko and Longines occupy the upper-right quadrant, reflecting distinct value propositions - Premium timepieces (yellower/greener hues) show tighter clustering, suggesting standardized luxury attributes - Smaller, specialized clusters indicate distinct horological collections and style categories #### t-SNE Visualization ![t-SNE Analysis](https://raw.githubusercontent.com/calicartels/watch-market-gnn-code/main/images/5.png) T-SNE analysis reveals clear market stratification with logarithmic pricing from $50 to $3.2M: - **Entry-Level Segment ($50-$4,000)** - Anchored by Seiko in the left segment - High volume, accessible luxury positioning - **Mid-Range Segment ($4,000-$35,000)** - Occupies central space - Shows competitive positioning between brands - Cartier demonstrates strategic positioning between luxury and mid-range - **Ultra-Luxury Segment ($35,000-$3.2M)** - Dominated by Patek Philippe and Audemars Piguet - Clear separation in the right segment - Strong brand clustering indicating market alignment #### PCA Analysis ![PCA Visualization](https://raw.githubusercontent.com/calicartels/watch-market-gnn-code/main/images/6.png) Principal Component Analysis provides robust market insights with 56.6% total explained variance: - **First Principal Component (31.3%)** - Predominantly captures price dynamics - Shows clear separation between market segments - **Second Principal Component (25.3%)** - Reflects brand positioning and design philosophies - Reveals vertical dispersion indicating intra-brand diversity - **Brand Trajectory** - Natural progression from Seiko through Longines, Breitling, and Omega - Culminates in Rolex and Patek Philippe - Diagonal trend line serves as a market positioning indicator - **Market Implications** - Successful brands occupy optimal positions along both dimensions - Clear differentiation between adjacent competitors - Evidence of strategic market positioning #### Network Visualizations **Force-Directed Graph** ![Force-Directed Graph](https://raw.githubusercontent.com/calicartels/watch-market-gnn-code/main/images/7.png) The force-directed layout reveals natural market clustering: - Richard Mille's peripheral positioning highlights ultra-luxury strategy - Dense central clustering shows mainstream luxury brand interconnectivity - Edge patterns reveal shared market characteristics - Node proximity indicates competitive positioning **Starburst Visualization** ![Starburst Graph](https://raw.githubusercontent.com/calicartels/watch-market-gnn-code/main/images/8.png) Radial architecture provides a hierarchical market perspective: - Central node represents the overall market - Green nodes show brand territories with strategic spacing - Blue peripheral nodes indicate individual timepieces - Node density reveals: - Brand portfolio breadth - Market penetration depth - Segment diversification - Balanced spacing between brand nodes indicates market segmentation ## Ethics and Limitations ### Data Collection and Privacy - Dataset consists of publicly available watch listings - No personal information, seller details, or private transaction data - Serial numbers and identifying marks removed - Strict privacy standards maintained throughout collection ### Known Biases #### Connection Strength Bias - Edge weights and connections based on author's domain expertise - Similarity thresholds (70%) chosen based on personal market understanding - Brand value weightings reflect author's market analysis - Connection strengths may not universally reflect all market perspectives #### Market Representation Bias - Predominantly represents online listings - May not fully capture private sales and in-person transactions - Popular brands overrepresented (Rolex 25%, Omega 14%) - Limited editions and rare pieces underrepresented #### Temporal Bias - Stronger representation of recent listings - Historical data may be underrepresented - Current market conditions more heavily weighted - Seasonal variations may affect price patterns #### Brand and Model Bias - Skewed toward mainstream luxury brands - Limited representation of boutique manufacturers - Popular models have more data points - Vintage and discontinued models may lack comprehensive data #### Price Bias - Asking prices may differ from actual transaction values - Regional price variations not fully captured - Currency conversion effects on price relationships - Market fluctuations may not be fully represented ### Usage Guidelines #### Appropriate Uses - Market research and analysis - Academic research - Watch relationship modeling - Price trend studies - Educational purposes #### Prohibited Uses - Price manipulation or market distortion - Unfair trading practices - Personal data extraction - Misleading market analysis - Anti-competitive practices ### License This dataset is released under the Apache 2.0 License, which allows: - Commercial use - Modification - Distribution - Private use While requiring: - License and copyright notice - State changes - Preserve attributions ## Usage ### Required Files The dataset consists of three main files: - `watch_gnn_data.pt` (315 MB): Main PyTorch Geometric data object - `edges.npz` (20.5 MB): Edge information - `features.npy` (596 MB): Node features ### Loading the Dataset ```python import torch from torch_geometric.data import Data # Load the main dataset data = torch.load('watch_gnn_data.pt') ``` #### Access components ``` node_features = data.x # Shape: [284491, combined_embedding_dim] edge_index = data.edge_index # Shape: [2, num_edges] edge_attr = data.edge_attr # Shape: [num_edges, 1] ``` #### For direct feature access ``` features = np.load('features.npy') ``` #### Get number of nodes ``` num_nodes = data.num_nodes ``` #### Get number of edges ``` num_edges = data.num_edges ``` #### Find similar watches (k-nearest neighbors) ``` def find_similar_watches(watch_id, k=5): # Get watch features watch_features = data.x[watch_id] # Calculate similarities similarities = torch.cosine_similarity( watch_features.unsqueeze(0), data.x, dim=1 ) # Get top k similar watches _, indices = similarities.topk(k+1) # +1 to exclude self return indices[1:] # Exclude self # Get watch features def get_watch_features(watch_id): return data.x[watch_id] ``` ## Note - The dataset is optimized for PyTorch Geometric operations - Recommended to use GPU for large-scale operations - Consider batch processing for memory efficiency