{
  "id": 5972,
  "title": "IDCG",
  "url": "/competitions/expedia-personalized-sort/discussion/5972",
  "author_name": "",
  "post_date": "2013-10-07T09:46:57.287Z",
  "votes": null,
  "comment_count": 2,
  "views": 1471,
  "content": "<p>HI,</p>\n<p>&nbsp;</p>\n<p>I need help with calculating IDCG</p>\n<p>I calculate the DCG for each query, ie for each list of hotels (ordered by relevance) returned by my recommendation system&nbsp;and I use the validation set to build the ideal order of hotels and calculate IDCG.&nbsp;is it true?</p>",
  "messages": [
    {
      "id": "32078",
      "postDate": "10/07/2013 09:46:57",
      "content": "<p>HI,</p>\n<p>&nbsp;</p>\n<p>I need help with calculating IDCG</p>\n<p>I calculate the DCG for each query, ie for each list of hotels (ordered by relevance) returned by my recommendation system&nbsp;and I use the validation set to build the ideal order of hotels and calculate IDCG.&nbsp;is it true?</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "32098",
      "postDate": "10/07/2013 21:29:26",
      "content": "<p>IDCG is the maximum possible value of DCG for a given set of results. You get it by computing DCG on the list of hotels, sorted by their relevance(the ground truth label). That is, it is the value of DCG that you would get if your ranking was perfect. The DCG that you compute for the numerator of NDCG is based on the order of the hotels that your ranking system produces.</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "32101",
      "postDate": "10/08/2013 07:01:08",
      "content": "<p>thank you</p>",
      "rawMarkdown": "",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 32098,
      "author_name": "davidthaler",
      "author_url": "",
      "post_date": "10/07/2013 21:29:26",
      "content": "<p>IDCG is the maximum possible value of DCG for a given set of results. You get it by computing DCG on the list of hotels, sorted by their relevance(the ground truth label). That is, it is the value of DCG that you would get if your ranking was perfect. The DCG that you compute for the numerator of NDCG is based on the order of the hotels that your ranking system produces.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 32101,
      "author_name": "nasserine",
      "author_url": "",
      "post_date": "10/08/2013 07:01:08",
      "content": "<p>thank you</p>",
      "votes": null,
      "replies": []
    }
  ],
  "raw_markdown_by_id": {
    "32078": "",
    "32098": "",
    "32101": ""
  },
  "source": "meta"
}