{
  "id": 637545,
  "title": "Solution Overview — 44th Place",
  "content": "<h4><strong>1. Data Preprocessing</strong></h4>\n<p>1.1 <strong>Applied Etiq + ChatGPT assisted preprocessing</strong> to automatically detect feature issues and generate correction rules.\n1.2 Removed the previous deduplication step used after merging tables — <strong>aggregation was needed</strong>, and deduplication would incorrectly discard valuable records.\n1.3 <strong>Manually corrected time formats</strong> based on distribution inspection and actual value patterns.\n1.4 Used <strong>Sweetviz for EDA</strong> to visualize distributions and detect anomalies.\n1.5 For <strong>Light, Weather, and other categorical attributes</strong>, performed <strong>custom normalization</strong> and format correction based on observed values.</p>\n<h2>1.6 Unified <strong>rare categories</strong> and categories <strong>absent in the test set</strong> into an <code>\"other\"</code> class to improve model robustness.</h2>\n<h4><strong>2. Modeling</strong></h4>\n<p>2.1 The main framework used was <strong>AutoGluon</strong>, which provided strong baseline performance with minimal manual tuning.</p>\n<h2>2.2 Experimented with <strong>automated feature processing and Stacking using OOF</strong> (out-of-fold) predictions.</h2>\n<h3><strong>Notes &amp; Observations</strong></h3>\n<p>The <strong>public leaderboard and local cross-validation were heavily misaligned</strong>, causing significant difficulty during model development. After post-competition analysis, I found that <strong>local CV was more reliable</strong>.\nPost-competition, I combined <strong>OOF files from my notebook and open-source notebook</strong>, and then applied <strong>GPU-accelerated Stacking</strong>, which led to a substantial improvement in performance.</p>",
  "comments": [],
  "comment_count": 0,
  "messages": [
    {
      "id": 3344363,
      "postDate": "2025-11-22T13:58:45.690Z",
      "content": "<h4><strong>1. Data Preprocessing</strong></h4>\n<p>1.1 <strong>Applied Etiq + ChatGPT assisted preprocessing</strong> to automatically detect feature issues and generate correction rules.\n1.2 Removed the previous deduplication step used after merging tables — <strong>aggregation was needed</strong>, and deduplication would incorrectly discard valuable records.\n1.3 <strong>Manually corrected time formats</strong> based on distribution inspection and actual value patterns.\n1.4 Used <strong>Sweetviz for EDA</strong> to visualize distributions and detect anomalies.\n1.5 For <strong>Light, Weather, and other categorical attributes</strong>, performed <strong>custom normalization</strong> and format correction based on observed values.</p>\n<h2>1.6 Unified <strong>rare categories</strong> and categories <strong>absent in the test set</strong> into an <code>\"other\"</code> class to improve model robustness.</h2>\n<h4><strong>2. Modeling</strong></h4>\n<p>2.1 The main framework used was <strong>AutoGluon</strong>, which provided strong baseline performance with minimal manual tuning.</p>\n<h2>2.2 Experimented with <strong>automated feature processing and Stacking using OOF</strong> (out-of-fold) predictions.</h2>\n<h3><strong>Notes &amp; Observations</strong></h3>\n<p>The <strong>public leaderboard and local cross-validation were heavily misaligned</strong>, causing significant difficulty during model development. After post-competition analysis, I found that <strong>local CV was more reliable</strong>.\nPost-competition, I combined <strong>OOF files from my notebook and open-source notebook</strong>, and then applied <strong>GPU-accelerated Stacking</strong>, which led to a substantial improvement in performance.</p>",
      "rawMarkdown": "\n\n#### **1. Data Preprocessing**\n\n1.1 **Applied Etiq + ChatGPT assisted preprocessing** to automatically detect feature issues and generate correction rules.\n1.2 Removed the previous deduplication step used after merging tables — **aggregation was needed**, and deduplication would incorrectly discard valuable records.\n1.3 **Manually corrected time formats** based on distribution inspection and actual value patterns.\n1.4 Used **Sweetviz for EDA** to visualize distributions and detect anomalies.\n1.5 For **Light, Weather, and other categorical attributes**, performed **custom normalization** and format correction based on observed values.\n1.6 Unified **rare categories** and categories **absent in the test set** into an `\"other\"` class to improve model robustness.\n\n---\n\n#### **2. Modeling**\n\n2.1 The main framework used was **AutoGluon**, which provided strong baseline performance with minimal manual tuning.\n2.2 Experimented with **automated feature processing and Stacking using OOF** (out-of-fold) predictions.\n\n---\n\n### **Notes & Observations**\n\nThe **public leaderboard and local cross-validation were heavily misaligned**, causing significant difficulty during model development. After post-competition analysis, I found that **local CV was more reliable**.\n\nPost-competition, I combined **OOF files from my notebook and open-source notebook**, and then applied **GPU-accelerated Stacking**, which led to a substantial improvement in performance.\n ",
      "votes": 1
    }
  ],
  "complete": true,
  "source": "live",
  "fetched_at": "2026-10-19T16:27:27Z",
  "competition_id": 117343,
  "competition_slug": "etiq-roadsense",
  "team_id": 14590933,
  "solution_url": "/competitions/etiq-roadsense/writeups/solution-overview-44th-place"
}