{
  "id": 328167,
  "title": "CV vs LB thread",
  "url": "/competitions/AI4Code/discussion/328167",
  "author_name": "yuanzhe zhou",
  "post_date": "2022-05-31T10:04:50.713000",
  "votes": 21,
  "comment_count": 12,
  "views": 0,
  "content": "<p>It's a bit early, but why not starting this typical thread. I find local cv and LB correlate very well.</p>\n<p>My local cv: 0.8540   LB: 0.8556</p>",
  "messages": [
    {
      "id": 1806578,
      "postDate": "2022-05-31T10:04:50.713Z",
      "content": "<p>It's a bit early, but why not starting this typical thread. I find local cv and LB correlate very well.</p>\n<p>My local cv: 0.8540   LB: 0.8556</p>",
      "rawMarkdown": "It's a bit early, but why not starting this typical thread. I find local cv and LB correlate very well.\n\nMy local cv: 0.8540   LB: 0.8556",
      "votes": 21
    },
    {
      "id": 1811836,
      "postDate": "2022-06-05T07:47:29.477Z",
      "content": "<p>I'm currently using single train-dev split rather than CV to save the running time.<br>\nWhen I used 1% of the dataset for the dev split (roughly 1000 notebooks, of course removed all forked notebooks) the dev scores are about 0.01-0.02 point higher than LB scores.<br>\nNow I'm using 10% for the dev (≒10000 notebooks) and the latest LB score became much closer to the dev score, the difference is now about 0.001 point.</p>\n<p>Maybe my 1%-size dev split has too many notebooks that are not forked but have copy-and-paste cells from/to notebooks in the train split.</p>",
      "rawMarkdown": "I'm currently using single train-dev split rather than CV to save the running time.\nWhen I used 1% of the dataset for the dev split (roughly 1000 notebooks, of course removed all forked notebooks) the dev scores are about 0.01-0.02 point higher than LB scores.\nNow I'm using 10% for the dev (≒10000 notebooks) and the latest LB score became much closer to the dev score, the difference is now about 0.001 point.\n\nMaybe my 1%-size dev split has too many notebooks that are not forked but have copy-and-paste cells from/to notebooks in the train split.",
      "votes": 4,
      "replies": [
        {
          "id": 1872321,
          "postDate": "2022-07-26T20:24:35.070Z",
          "content": "<p><a href=\"https://www.kaggle.com/yufuin\" target=\"_blank\">@yufuin</a> Are you just doing a random split? How are you removing forks?</p>",
          "rawMarkdown": "@yufuin Are you just doing a random split? How are you removing forks?"
        },
        {
          "id": 1872792,
          "postDate": "2022-07-27T08:33:43.467Z",
          "content": "<p>When I posted the comment I simply removed all of notebooks that have parent_id, then randomly split.<br>\nHowever I'm not using the split now. Since it's two weeks before the deadline, I will refrain from sharing my current method in detail. (sorry!)</p>",
          "rawMarkdown": "When I posted the comment I simply removed all of notebooks that have parent_id, then randomly split.\nHowever I'm not using the split now. Since it's two weeks before the deadline, I will refrain from sharing my current method in detail. (sorry!)",
          "votes": 2
        },
        {
          "id": 1872800,
          "postDate": "2022-07-27T08:41:55.560Z",
          "rawMarkdown": "",
          "isDeleted": true
        },
        {
          "id": 1872803,
          "postDate": "2022-07-27T08:43:03.750Z",
          "content": "<p>I was dropping kernels without an ancestor_id and taking only 1 kernel with a unique ancestor_id.</p>",
          "rawMarkdown": "I was dropping kernels without an ancestor_id and taking only 1 kernel with a unique ancestor_id."
        },
        {
          "id": 1872861,
          "postDate": "2022-07-27T09:25:00.863Z",
          "content": "<p><a href=\"https://www.kaggle.com/yufuin\" target=\"_blank\">@yufuin</a> this is also helpful. Thanks :) Good luck!</p>",
          "rawMarkdown": "@yufuin this is also helpful. Thanks :) Good luck!"
        }
      ]
    },
    {
      "id": 1872451,
      "postDate": "2022-07-27T01:32:31.880Z",
      "content": "<p>I'm using 8/2 split with group by ansestor id, it seems online is 6-10k lower then offline. But I found there are so many duplicates even grouby by ansestor id is not enough maybe.</p>",
      "rawMarkdown": "I'm using 8/2 split with group by ansestor id, it seems online is 6-10k lower then offline. But I found there are so many duplicates even grouby by ansestor id is not enough maybe.",
      "votes": 1,
      "replies": [
        {
          "id": 1872687,
          "postDate": "2022-07-27T07:13:52.903Z",
          "content": "<p>I was trying to get away with 2.5% validation. But it wasn't the best idea.</p>\n<p><a href=\"https://www.kaggle.com/goldenlock\" target=\"_blank\">@goldenlock</a> you are not dropping any notebooks? In training or validation?</p>",
          "rawMarkdown": "I was trying to get away with 2.5% validation. But it wasn't the best idea.\n\n@goldenlock you are not dropping any notebooks? In training or validation?"
        },
        {
          "id": 1874009,
          "postDate": "2022-07-28T02:37:03.380Z",
          "content": "<p><a href=\"https://www.kaggle.com/crodoc\" target=\"_blank\">@crodoc</a>  Yes using all data. Another finding is though online much lower score then offline, my offline improvement reflected well online so not much a problem maybe.</p>",
          "rawMarkdown": "@crodoc  Yes using all data. Another finding is though online much lower score then offline, my offline improvement reflected well online so not much a problem maybe.",
          "votes": 1
        },
        {
          "id": 1874152,
          "postDate": "2022-07-28T05:23:51.667Z",
          "content": "<p>Yes, same thing for us when we used 10% of data. Thanks a lot!</p>",
          "rawMarkdown": "Yes, same thing for us when we used 10% of data. Thanks a lot!"
        }
      ]
    },
    {
      "id": 1809614,
      "postDate": "2022-06-02T21:12:11.843Z",
      "content": "<p>Maybe because the notebooks are for the same time period, but the private test set will be for future !</p>",
      "rawMarkdown": "Maybe because the notebooks are for the same time period, but the private test set will be for future !",
      "replies": [
        {
          "id": 1809776,
          "postDate": "2022-06-03T03:46:04.227Z",
          "content": "<p>The authors of notebooks will be quite different, there will probably be shake up.</p>",
          "rawMarkdown": "The authors of notebooks will be quite different, there will probably be shake up.",
          "votes": 1
        }
      ]
    }
  ],
  "comments": [
    {
      "id": 1811836,
      "author_name": "yufuin",
      "author_url": "",
      "post_date": "2022-06-05T07:47:29.477000",
      "content": "<p>I'm currently using single train-dev split rather than CV to save the running time.<br>\nWhen I used 1% of the dataset for the dev split (roughly 1000 notebooks, of course removed all forked notebooks) the dev scores are about 0.01-0.02 point higher than LB scores.<br>\nNow I'm using 10% for the dev (≒10000 notebooks) and the latest LB score became much closer to the dev score, the difference is now about 0.001 point.</p>\n<p>Maybe my 1%-size dev split has too many notebooks that are not forked but have copy-and-paste cells from/to notebooks in the train split.</p>",
      "votes": 4,
      "replies": [
        {
          "id": 1872321,
          "author_name": "CroDoc",
          "author_url": "",
          "post_date": "2022-07-26T20:24:35.070000",
          "content": "<p><a href=\"https://www.kaggle.com/yufuin\" target=\"_blank\">@yufuin</a> Are you just doing a random split? How are you removing forks?</p>",
          "votes": 0,
          "replies": []
        },
        {
          "id": 1872792,
          "author_name": "yufuin",
          "author_url": "",
          "post_date": "2022-07-27T08:33:43.467000",
          "content": "<p>When I posted the comment I simply removed all of notebooks that have parent_id, then randomly split.<br>\nHowever I'm not using the split now. Since it's two weeks before the deadline, I will refrain from sharing my current method in detail. (sorry!)</p>",
          "votes": 2,
          "replies": []
        },
        {
          "id": 1872800,
          "author_name": "",
          "author_url": "",
          "post_date": "2022-07-27T08:41:55.560000",
          "content": "",
          "votes": 0,
          "replies": []
        },
        {
          "id": 1872803,
          "author_name": "CroDoc",
          "author_url": "",
          "post_date": "2022-07-27T08:43:03.750000",
          "content": "<p>I was dropping kernels without an ancestor_id and taking only 1 kernel with a unique ancestor_id.</p>",
          "votes": 0,
          "replies": []
        },
        {
          "id": 1872861,
          "author_name": "CroDoc",
          "author_url": "",
          "post_date": "2022-07-27T09:25:00.863000",
          "content": "<p><a href=\"https://www.kaggle.com/yufuin\" target=\"_blank\">@yufuin</a> this is also helpful. Thanks :) Good luck!</p>",
          "votes": 0,
          "replies": []
        }
      ]
    },
    {
      "id": 1872451,
      "author_name": "gezi",
      "author_url": "",
      "post_date": "2022-07-27T01:32:31.880000",
      "content": "<p>I'm using 8/2 split with group by ansestor id, it seems online is 6-10k lower then offline. But I found there are so many duplicates even grouby by ansestor id is not enough maybe.</p>",
      "votes": 1,
      "replies": [
        {
          "id": 1872687,
          "author_name": "CroDoc",
          "author_url": "",
          "post_date": "2022-07-27T07:13:52.903000",
          "content": "<p>I was trying to get away with 2.5% validation. But it wasn't the best idea.</p>\n<p><a href=\"https://www.kaggle.com/goldenlock\" target=\"_blank\">@goldenlock</a> you are not dropping any notebooks? In training or validation?</p>",
          "votes": 0,
          "replies": []
        },
        {
          "id": 1874009,
          "author_name": "gezi",
          "author_url": "",
          "post_date": "2022-07-28T02:37:03.380000",
          "content": "<p><a href=\"https://www.kaggle.com/crodoc\" target=\"_blank\">@crodoc</a>  Yes using all data. Another finding is though online much lower score then offline, my offline improvement reflected well online so not much a problem maybe.</p>",
          "votes": 1,
          "replies": []
        },
        {
          "id": 1874152,
          "author_name": "CroDoc",
          "author_url": "",
          "post_date": "2022-07-28T05:23:51.667000",
          "content": "<p>Yes, same thing for us when we used 10% of data. Thanks a lot!</p>",
          "votes": 0,
          "replies": []
        }
      ]
    },
    {
      "id": 1809614,
      "author_name": "Alireza",
      "author_url": "",
      "post_date": "2022-06-02T21:12:11.843000",
      "content": "<p>Maybe because the notebooks are for the same time period, but the private test set will be for future !</p>",
      "votes": 0,
      "replies": [
        {
          "id": 1809776,
          "author_name": "yuanzhe zhou",
          "author_url": "",
          "post_date": "2022-06-03T03:46:04.227000",
          "content": "<p>The authors of notebooks will be quite different, there will probably be shake up.</p>",
          "votes": 1,
          "replies": []
        }
      ]
    }
  ],
  "raw_markdown_by_id": {
    "1806578": "It's a bit early, but why not starting this typical thread. I find local cv and LB correlate very well.\n\nMy local cv: 0.8540   LB: 0.8556",
    "1811836": "I'm currently using single train-dev split rather than CV to save the running time.\nWhen I used 1% of the dataset for the dev split (roughly 1000 notebooks, of course removed all forked notebooks) the dev scores are about 0.01-0.02 point higher than LB scores.\nNow I'm using 10% for the dev (≒10000 notebooks) and the latest LB score became much closer to the dev score, the difference is now about 0.001 point.\n\nMaybe my 1%-size dev split has too many notebooks that are not forked but have copy-and-paste cells from/to notebooks in the train split.",
    "1872451": "I'm using 8/2 split with group by ansestor id, it seems online is 6-10k lower then offline. But I found there are so many duplicates even grouby by ansestor id is not enough maybe.",
    "1809614": "Maybe because the notebooks are for the same time period, but the private test set will be for future !"
  }
}