{
  "id": 73497,
  "title": "Something wicked this way comes",
  "url": "/competitions/elo-merchant-category-recommendation/discussion/73497",
  "author_name": "",
  "post_date": "2018-12-03T16:28:03.925360800Z",
  "votes": 15,
  "comment_count": 17,
  "views": 0,
  "content": "<p>I was wondering if anybody had a similar experience: I have decided to focus on feature engineering + single model for now (lgbm with 10-fold cross validation). Variation across folds - much higher than the distance between my current position and the top - is somewhat annoying, but not uncommon. What I find more peculiar is that it feels like almost any feature I create, it improves the score in cv, but makes the LB worse. I have tried all kinds of aggregates, including merchants info - and the effect stays the same =&gt; I am unable to beat my original attempt scoring 3.709. </p>\n\n<p>Really curious about experience others are having.</p>",
  "messages": [
    {
      "id": "432265",
      "postDate": "12/03/2018 16:28:03",
      "content": "<p>I was wondering if anybody had a similar experience: I have decided to focus on feature engineering + single model for now (lgbm with 10-fold cross validation). Variation across folds - much higher than the distance between my current position and the top - is somewhat annoying, but not uncommon. What I find more peculiar is that it feels like almost any feature I create, it improves the score in cv, but makes the LB worse. I have tried all kinds of aggregates, including merchants info - and the effect stays the same =&gt; I am unable to beat my original attempt scoring 3.709. </p>\n\n<p>Really curious about experience others are having.</p>",
      "rawMarkdown": "I was wondering if anybody had a similar experience: I have decided to focus on feature engineering + single model for now (lgbm with 10-fold cross validation). Variation across folds - much higher than the distance between my current position and the top - is somewhat annoying, but not uncommon. What I find more peculiar is that it feels like almost any feature I create, it improves the score in cv, but makes the LB worse. I have tried all kinds of aggregates, including merchants info - and the effect stays the same =&gt; I am unable to beat my original attempt scoring 3.709. \n\nReally curious about experience others are having.",
      "votes": null
    },
    {
      "id": "432278",
      "postDate": "12/03/2018 16:53:22",
      "content": "<p>The same experience ...</p>",
      "rawMarkdown": "The same experience ...",
      "votes": null
    },
    {
      "id": "432280",
      "postDate": "12/03/2018 16:55:25",
      "content": "<p>Same here. I kind of feel a little disappointed now.</p>",
      "rawMarkdown": "Same here. I kind of feel a little disappointed now.",
      "votes": null
    },
    {
      "id": "432323",
      "postDate": "12/03/2018 18:12:46",
      "content": "<p>Same here :/</p>",
      "rawMarkdown": "Same here :/",
      "votes": null
    },
    {
      "id": "432337",
      "postDate": "12/03/2018 18:27:29",
      "content": "<p>Same here. New features improve CV but lower LB. I am tired</p>",
      "rawMarkdown": "Same here. New features improve CV but lower LB. I am tired",
      "votes": null
    },
    {
      "id": "432358",
      "postDate": "12/03/2018 18:58:04",
      "content": "<p>Yeah, I'm about to think about giving up. I just added merchants.csv features in, and no LB improvement. </p>",
      "rawMarkdown": "Yeah, I'm about to think about giving up. I just added merchants.csv features in, and no LB improvement.",
      "votes": null
    },
    {
      "id": "432359",
      "postDate": "12/03/2018 19:03:50",
      "content": "<p>like nailing jelly to the wall</p>",
      "rawMarkdown": "like nailing jelly to the wall",
      "votes": null
    },
    {
      "id": "432383",
      "postDate": "12/03/2018 19:40:45",
      "content": "<p>Same experience here.</p>",
      "rawMarkdown": "Same experience here.",
      "votes": null
    },
    {
      "id": "432385",
      "postDate": "12/03/2018 19:42:22",
      "content": "<p>I'd also add that because of the randomness of the features and the target, it's likely the top of the leaderboard will see a massive shuffle on the private leaderboard when the other 70% of the data is used due to overfitting on lucky seeds. </p>",
      "rawMarkdown": "I'd also add that because of the randomness of the features and the target, it's likely the top of the leaderboard will see a massive shuffle on the private leaderboard when the other 70% of the data is used due to overfitting on lucky seeds.",
      "votes": null
    },
    {
      "id": "432388",
      "postDate": "12/03/2018 19:44:07",
      "content": "<p>Definitely.. people seem to have hit upon a seed of 11 for the lightgbm model and 15 for Kfolds.. but that should hopefully change on the private LB</p>",
      "rawMarkdown": "Definitely.. people seem to have hit upon a seed of 11 for the lightgbm model and 15 for Kfolds.. but that should hopefully change on the private LB",
      "votes": null
    },
    {
      "id": "432462",
      "postDate": "12/03/2018 22:29:28",
      "content": "<p>Yep, I'm also getting stuck in this world... &gt;.&lt; Hopefully trusting my CV is the way to go?</p>",
      "rawMarkdown": "Yep, I'm also getting stuck in this world... &gt;.&lt; Hopefully trusting my CV is the way to go?",
      "votes": null
    },
    {
      "id": "432479",
      "postDate": "12/03/2018 23:39:24",
      "content": "<p>One can only hope. </p>",
      "rawMarkdown": "One can only hope.",
      "votes": null
    },
    {
      "id": "432584",
      "postDate": "12/04/2018 04:24:21",
      "content": "<p>From my experience, when cv improves, lb  improves (now cv ~ 3.653, lb ~ 3.699, ~80 features).\nP/S : merchants.csv features didn't help my cv at all.</p>",
      "rawMarkdown": "From my experience, when cv improves, lb  improves (now cv ~ 3.653, lb ~ 3.699, ~80 features).\nP/S : merchants.csv features didn't help my cv at all.",
      "votes": null
    },
    {
      "id": "432907",
      "postDate": "12/04/2018 13:03:19",
      "content": "<p>@Chau Ngoc Huynh</p>\n\n<p>Same on my side... Really strange.</p>",
      "rawMarkdown": "Chau Ngoc Huynh\n\nSame on my side... Really strange.",
      "votes": null
    },
    {
      "id": "433999",
      "postDate": "12/05/2018 18:46:50",
      "content": "<p>For me aggregations definitely help to improve both cv ad lb, but manual features (like purchase_amount / date_diff) improve only local cv. It seems that it's time to speak about reliable cv scheme.</p>",
      "rawMarkdown": "For me aggregations definitely help to improve both cv ad lb, but manual features (like purchase\\_amount / date\\_diff) improve only local cv. It seems that it's time to speak about reliable cv scheme.",
      "votes": null
    },
    {
      "id": "434004",
      "postDate": "12/05/2018 18:53:20",
      "content": "<p>Exactly, I've tried 50 different features already. No manually created features work for me. </p>",
      "rawMarkdown": "Exactly, I've tried 50 different features already. No manually created features work for me.",
      "votes": null
    },
    {
      "id": "441516",
      "postDate": "12/18/2018 18:20:52",
      "content": "<p>There are some high correlations in Merchants Data. Perhaps that explains why the features we think will be important - are not important at all</p>",
      "rawMarkdown": "There are some high correlations in Merchants Data. Perhaps that explains why the features we think will be important - are not important at all",
      "votes": null
    },
    {
      "id": "441742",
      "postDate": "12/19/2018 02:05:45",
      "content": "<p>I just joined df_hist with merchant data then did some agg, but got a worse cv score and lb score.</p>",
      "rawMarkdown": "I just joined df_hist with merchant data then did some agg, but got a worse cv score and lb score.",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 432278,
      "author_name": "mileta1976",
      "author_url": "",
      "post_date": "12/03/2018 16:53:22",
      "content": "<p>The same experience ...</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 432280,
      "author_name": "jinjunding",
      "author_url": "",
      "post_date": "12/03/2018 16:55:25",
      "content": "<p>Same here. I kind of feel a little disappointed now.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 432323,
      "author_name": "silverstone1903",
      "author_url": "",
      "post_date": "12/03/2018 18:12:46",
      "content": "<p>Same here :/</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 432337,
      "author_name": "deffro",
      "author_url": "",
      "post_date": "12/03/2018 18:27:29",
      "content": "<p>Same here. New features improve CV but lower LB. I am tired</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 432358,
      "author_name": "delayedkarma",
      "author_url": "",
      "post_date": "12/03/2018 18:58:04",
      "content": "<p>Yeah, I'm about to think about giving up. I just added merchants.csv features in, and no LB improvement. </p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 432359,
      "author_name": "franzxschmid",
      "author_url": "",
      "post_date": "12/03/2018 19:03:50",
      "content": "<p>like nailing jelly to the wall</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 432383,
      "author_name": "hampsonw",
      "author_url": "",
      "post_date": "12/03/2018 19:40:45",
      "content": "<p>Same experience here.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 432385,
      "author_name": "hampsonw",
      "author_url": "",
      "post_date": "12/03/2018 19:42:22",
      "content": "<p>I'd also add that because of the randomness of the features and the target, it's likely the top of the leaderboard will see a massive shuffle on the private leaderboard when the other 70% of the data is used due to overfitting on lucky seeds. </p>",
      "votes": null,
      "replies": [
        {
          "id": 432388,
          "author_name": "delayedkarma",
          "author_url": "",
          "post_date": "12/03/2018 19:44:07",
          "content": "<p>Definitely.. people seem to have hit upon a seed of 11 for the lightgbm model and 15 for Kfolds.. but that should hopefully change on the private LB</p>",
          "votes": null,
          "replies": []
        }
      ]
    },
    {
      "id": 432462,
      "author_name": "peterhurford",
      "author_url": "",
      "post_date": "12/03/2018 22:29:28",
      "content": "<p>Yep, I'm also getting stuck in this world... &gt;.&lt; Hopefully trusting my CV is the way to go?</p>",
      "votes": null,
      "replies": [
        {
          "id": 432479,
          "author_name": "delayedkarma",
          "author_url": "",
          "post_date": "12/03/2018 23:39:24",
          "content": "<p>One can only hope. </p>",
          "votes": null,
          "replies": []
        }
      ]
    },
    {
      "id": 432584,
      "author_name": "chauhuynh",
      "author_url": "",
      "post_date": "12/04/2018 04:24:21",
      "content": "<p>From my experience, when cv improves, lb  improves (now cv ~ 3.653, lb ~ 3.699, ~80 features).\nP/S : merchants.csv features didn't help my cv at all.</p>",
      "votes": null,
      "replies": [
        {
          "id": 432907,
          "author_name": "pfichou",
          "author_url": "",
          "post_date": "12/04/2018 13:03:19",
          "content": "<p>@Chau Ngoc Huynh</p>\n\n<p>Same on my side... Really strange.</p>",
          "votes": null,
          "replies": []
        }
      ]
    },
    {
      "id": 433999,
      "author_name": "kailex",
      "author_url": "",
      "post_date": "12/05/2018 18:46:50",
      "content": "<p>For me aggregations definitely help to improve both cv ad lb, but manual features (like purchase_amount / date_diff) improve only local cv. It seems that it's time to speak about reliable cv scheme.</p>",
      "votes": null,
      "replies": [
        {
          "id": 434004,
          "author_name": "jinjunding",
          "author_url": "",
          "post_date": "12/05/2018 18:53:20",
          "content": "<p>Exactly, I've tried 50 different features already. No manually created features work for me. </p>",
          "votes": null,
          "replies": []
        }
      ]
    },
    {
      "id": 441516,
      "author_name": "roydatascience",
      "author_url": "",
      "post_date": "12/18/2018 18:20:52",
      "content": "<p>There are some high correlations in Merchants Data. Perhaps that explains why the features we think will be important - are not important at all</p>",
      "votes": null,
      "replies": [
        {
          "id": 441742,
          "author_name": "codlife",
          "author_url": "",
          "post_date": "12/19/2018 02:05:45",
          "content": "<p>I just joined df_hist with merchant data then did some agg, but got a worse cv score and lb score.</p>",
          "votes": null,
          "replies": []
        }
      ]
    }
  ],
  "raw_markdown_by_id": {
    "432265": "I was wondering if anybody had a similar experience: I have decided to focus on feature engineering + single model for now (lgbm with 10-fold cross validation). Variation across folds - much higher than the distance between my current position and the top - is somewhat annoying, but not uncommon. What I find more peculiar is that it feels like almost any feature I create, it improves the score in cv, but makes the LB worse. I have tried all kinds of aggregates, including merchants info - and the effect stays the same =&gt; I am unable to beat my original attempt scoring 3.709. \n\nReally curious about experience others are having.",
    "432278": "The same experience ...",
    "432280": "Same here. I kind of feel a little disappointed now.",
    "432323": "Same here :/",
    "432337": "Same here. New features improve CV but lower LB. I am tired",
    "432358": "Yeah, I'm about to think about giving up. I just added merchants.csv features in, and no LB improvement.",
    "432359": "like nailing jelly to the wall",
    "432383": "Same experience here.",
    "432385": "I'd also add that because of the randomness of the features and the target, it's likely the top of the leaderboard will see a massive shuffle on the private leaderboard when the other 70% of the data is used due to overfitting on lucky seeds.",
    "432388": "Definitely.. people seem to have hit upon a seed of 11 for the lightgbm model and 15 for Kfolds.. but that should hopefully change on the private LB",
    "432462": "Yep, I'm also getting stuck in this world... &gt;.&lt; Hopefully trusting my CV is the way to go?",
    "432479": "One can only hope.",
    "432584": "From my experience, when cv improves, lb  improves (now cv ~ 3.653, lb ~ 3.699, ~80 features).\nP/S : merchants.csv features didn't help my cv at all.",
    "432907": "Chau Ngoc Huynh\n\nSame on my side... Really strange.",
    "433999": "For me aggregations definitely help to improve both cv ad lb, but manual features (like purchase\\_amount / date\\_diff) improve only local cv. It seems that it's time to speak about reliable cv scheme.",
    "434004": "Exactly, I've tried 50 different features already. No manually created features work for me.",
    "441516": "There are some high correlations in Merchants Data. Perhaps that explains why the features we think will be important - are not important at all",
    "441742": "I just joined df_hist with merchant data then did some agg, but got a worse cv score and lb score."
  },
  "source": "meta"
}