{
  "id": 11542,
  "title": "About NULL value and meanings of some variables ",
  "url": "/competitions/avazu-ctr-prediction/discussion/11542",
  "author_name": "",
  "post_date": "2015-01-18T02:49:26.630Z",
  "votes": 1,
  "comment_count": 2,
  "views": 964,
  "content": "<p>I'm a new here. I was confused when doing some data clean work.</p>\n<p>First, I tried to find null value in datasets, and I just find some hash code which are most frequency such as site_id:85f751fd, site_domain:c4e18dd6. The result was reported by&nbsp;laserwolf in&nbsp;<a href=\"http://www.kaggle.com/c/avazu-ctr-prediction/forums/t/10819/unique-missing-train-and-test-values\">unique-missing-train-and-test-values</a>. But I'm not sured that's correct.</p>\n<p>And I found&nbsp;Steve Wang(admin) said that null is hashed to&nbsp;d41d8cd9 in&nbsp;<a href=\"https://www.kaggle.com/c/avazu-ctr-prediction/forums/t/10852/null-values-in-datasets\">null-values-in-datasets</a>. But I couldn't found&nbsp;d41d8cd9 in my dataset.</p>\n<p>So what's the answer, why admin hid NULL value?</p>\n<p>Second&#65292;I found&nbsp;Steve Wang mentioned 'device_make' in&nbsp;<a href=\"https://www.kaggle.com/c/avazu-ctr-prediction/forums/t/10729/welcome-to-avazu-ctr-prediction-contest\">welcome-to-avazu-ctr-prediction-contest</a>&nbsp;when talk about means of some variables, but I can't found the&nbsp;device_make in my dataset.&nbsp;Does&nbsp;I miss something?</p>",
  "messages": [
    {
      "id": "62847",
      "postDate": "01/18/2015 02:49:26",
      "content": "<p>I'm a new here. I was confused when doing some data clean work.</p>\n<p>First, I tried to find null value in datasets, and I just find some hash code which are most frequency such as site_id:85f751fd, site_domain:c4e18dd6. The result was reported by&nbsp;laserwolf in&nbsp;<a href=\"http://www.kaggle.com/c/avazu-ctr-prediction/forums/t/10819/unique-missing-train-and-test-values\">unique-missing-train-and-test-values</a>. But I'm not sured that's correct.</p>\n<p>And I found&nbsp;Steve Wang(admin) said that null is hashed to&nbsp;d41d8cd9 in&nbsp;<a href=\"https://www.kaggle.com/c/avazu-ctr-prediction/forums/t/10852/null-values-in-datasets\">null-values-in-datasets</a>. But I couldn't found&nbsp;d41d8cd9 in my dataset.</p>\n<p>So what's the answer, why admin hid NULL value?</p>\n<p>Second&#65292;I found&nbsp;Steve Wang mentioned 'device_make' in&nbsp;<a href=\"https://www.kaggle.com/c/avazu-ctr-prediction/forums/t/10729/welcome-to-avazu-ctr-prediction-contest\">welcome-to-avazu-ctr-prediction-contest</a>&nbsp;when talk about means of some variables, but I can't found the&nbsp;device_make in my dataset.&nbsp;Does&nbsp;I miss something?</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "62851",
      "postDate": "01/18/2015 05:52:51",
      "content": "<p>Due to some data problem, the competition was stopped in mid-November and restarted on Nov 19th with new data. All forum posts before Nov 19th are talking about old data, which had different hashes and some additional fields.</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "62890",
      "postDate": "01/19/2015 03:27:37",
      "content": "<p>[quote=laserwolf;62851]</p>\n<p>Due to some data problem, the competition was stopped in mid-November and restarted on Nov 19th with new data. All forum posts before Nov 19th are talking about old data, which had different hashes and some additional fields.</p>\n<p>[/quote]</p>\n<p>Thx. So we need to guess which hash code is NULL?</p>",
      "rawMarkdown": "",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 62851,
      "author_name": "vvarkey",
      "author_url": "",
      "post_date": "01/18/2015 05:52:51",
      "content": "<p>Due to some data problem, the competition was stopped in mid-November and restarted on Nov 19th with new data. All forum posts before Nov 19th are talking about old data, which had different hashes and some additional fields.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 62890,
      "author_name": "haibowu",
      "author_url": "",
      "post_date": "01/19/2015 03:27:37",
      "content": "<p>[quote=laserwolf;62851]</p>\n<p>Due to some data problem, the competition was stopped in mid-November and restarted on Nov 19th with new data. All forum posts before Nov 19th are talking about old data, which had different hashes and some additional fields.</p>\n<p>[/quote]</p>\n<p>Thx. So we need to guess which hash code is NULL?</p>",
      "votes": null,
      "replies": []
    }
  ],
  "raw_markdown_by_id": {
    "62847": "",
    "62851": "",
    "62890": ""
  },
  "source": "meta"
}