Update README.md

README.md

@@ -61,6 +61,21 @@ A comprehensive pipeline for archiving, processing, and analyzing Reddit data fr
 └── README.md                          # This documentation file
 ```
 
+## 🏆 **Data Validation Layer**
+
+The **original_schema_analysis** acts as a **data quality validation layer** before any substantive analysis.
+
+### **Phase 1 vs Phase 2 Analysis**
+```
+Original Schema Analysis              vs       Parquet Subreddits Analysis
+─────────────────────────────────────────────────────────────────────────────
+Raw data quality assessment                   Processed data insights
+Longitudinal (2005-2025)                      Cross-sectional (subreddit focus)
+Technical schema evolution                    Social/community patterns
+Data engineering perspective                  Social science perspective
+Low-level field statistics                    High-level behavioral patterns
+"What fields exist?"                          "What do people do?"
+```
 
 ## 📈 Dataset Statistics
 
@@ -136,7 +151,7 @@ A comprehensive pipeline for archiving, processing, and analyzing Reddit data fr
 
 ### Processed Data
 - **Format:** Apache Parquet
-- **Compression:** Snappy/GZIP (columnar)
+- **Compression:** Zst (columnar)
 - **Partitioning:** Year-based (2005-2025)
 - **Optimization:** Column pruning, predicate pushdown