{
  "id": 3594,
  "title": "How training data and test data are selected ?",
  "url": "/competitions/event-recommendation-engine-challenge/discussion/3594",
  "author_name": "",
  "post_date": "2013-01-14T16:08:57.993Z",
  "votes": null,
  "comment_count": 1,
  "views": 1131,
  "content": "<p>Hi all,</p>\r\n<p>I tried the popularity-based benchmark on both training and test data, but got very different MAP(training data 0.2501 and test 0.5281). I'm wondering how could this happen if the training and test data are randomly selected ? It seems the ratio of &quot;interest&quot;\r\n event in test data is much higher than that in training data......&nbsp;</p>\r\n<p>Can anyone give some explication on this? Thanks in advance~</p>",
  "messages": [
    {
      "id": "19294",
      "postDate": "01/14/2013 16:08:57",
      "content": "<p>Hi all,</p>\r\n<p>I tried the popularity-based benchmark on both training and test data, but got very different MAP(training data 0.2501 and test 0.5281). I'm wondering how could this happen if the training and test data are randomly selected ? It seems the ratio of &quot;interest&quot;\r\n event in test data is much higher than that in training data......&nbsp;</p>\r\n<p>Can anyone give some explication on this? Thanks in advance~</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "19336",
      "postDate": "01/15/2013 14:35:00",
      "content": "<p>never mind，it's because I did sth stupid.</p>",
      "rawMarkdown": "",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 19336,
      "author_name": "dingqi",
      "author_url": "",
      "post_date": "01/15/2013 14:35:00",
      "content": "<p>never mind，it's because I did sth stupid.</p>",
      "votes": null,
      "replies": []
    }
  ],
  "raw_markdown_by_id": {
    "19294": "",
    "19336": ""
  },
  "source": "meta"
}