{
  "id": 2003,
  "title": "Graph-based Features for Supervised Link Prediction",
  "url": "/competitions/FacebookRecruiting/discussion/2003",
  "author_name": "",
  "post_date": "2012-06-06T23:49:41.723Z",
  "votes": 27,
  "comment_count": 8,
  "views": 10266,
  "content": "<p>(alternate title: shameless self promotion...)</p>\r\n<p>Competitors may find this paper helpful.&nbsp; Good luck to all!</p>",
  "messages": [
    {
      "id": "11432",
      "postDate": "06/06/2012 23:49:41",
      "content": "<p>(alternate title: shameless self promotion...)</p>\r\n<p>Competitors may find this paper helpful.&nbsp; Good luck to all!</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "11437",
      "postDate": "06/07/2012 07:21:18",
      "content": "<p>(Igor's message said that he was unable to download the file before he edited the message)</p>\r\n<p>Sorry for the issue. This is a problem that arose in the past, and may be a bug with Chrome, how Azure is serving the files, or our site.</p>\r\n<p>If you have trouble downloading the file, please right click and &quot;Save File As ...&quot; and it should download fine. Alternatively, different browsers should work as well.</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "11624",
      "postDate": "06/15/2012 02:44:21",
      "content": "<p>Interesting, but I wonder how to choose the negtive sample? as you know, all connections are positive sample.</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "11627",
      "postDate": "06/15/2012 18:38:29",
      "content": "<p>This is your opportunity to demonstrate your skills on a real-world social network dataset, and show them your creativity, open-mindedness and tenacity in the face of an open-ended predictive modeling problem! And this time without cheating...</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "11668",
      "postDate": "06/17/2012 02:13:01",
      "content": "<p>Sorry, Thanks guys, the same to you.</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "11892",
      "postDate": "06/26/2012 13:02:48",
      "content": "<p>Got a quick question about the EdgeRank algorithm on pg 1240 of the pdf (not sure if EdgeRank is relevant to this competition or not atm, just asking in general):</p>\r\n<p>Eqn 5: &nbsp;Xn = (1-d)X0 &#43; d(A&#43;wA')Xn-1</p>\r\n<p>1. &nbsp;(A&#43;wA') as a whole must be row normalized? &nbsp;I ran a few quick iterations in Matlab, and the probabilities exploded. &nbsp;Some of them were wayyyy more than one. &nbsp;Row normalization would be equivalent to a uniform probability of chosing each link?</p>\r\n<p>2. &nbsp;I'm a little hazy on why this equation gives the probability of reaching whichever node in n steps. &nbsp;</p>\r\n<p>I understand the (1-d)X0 chunk. &nbsp;Am stuck on the other part which says d(A&#43;wA')Xn-1. &nbsp;If you multiply it out by hand slowly using 1st row as an example, I *think* it says something like &quot;(probability of going from node 1 to node 2)*(probability of being\r\n at node 2) &#43; (probability of going from node 1 to node 3)*(probability of being at node 3).......etc&quot;, and the entire result is supposed to be probability of being at node 1 after n steps??!!??? &nbsp;Why is this?</p>\r\n<p>If the entire (A&#43;wA') matrix were transposed, so that it was (probability of going from node 2 to node 1)*(Prob at node 2)&#43;(prob of going from node 3 to node 1)*(Prob at node 3)&#43;....etc, that would be straightforward to understand. &nbsp;If (A&#43;wA') were symmetric,\r\n it wouldn't matter, but it doesn't have to be...</p>\r\n<p>&nbsp;</p>\r\n<p>It's also *very* possible that I'm just suffering from lack of sleep..LOL. &nbsp;</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "12277",
      "postDate": "07/10/2012 19:20:11",
      "content": "<p>&nbsp;</p>\r\n<p style=\"padding-left:30px\">&quot;The training data for the Random Forests was obtained by<br>\r\ncreating eight independent validation sets, each consisting of<br>\r\n4,000 data points (2,000 real edges and 2,000 fake edges).<br>\r\nThese validation sets were constructed to approximate the<br>\r\ndistributions of nodes and edges seen in the test set.&quot;</p>\r\n<p>&nbsp;</p>\r\n<p>What method did you use?<br>\r\n<br>\r\n</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "12288",
      "postDate": "07/10/2012 23:57:36",
      "content": "<p>Snoopy, it's probably too late to reply to this but I didn't see it before. I also had a look at that paper and was puzzled by eq. 5. It is not correct (or at least, does not correspond with its description), since it does not yield a valid transition matrix.</p>\r\n<p>To fix it, (A&#43;wA') should be <em>column</em> normalized. Alternatively, you could normalize A and A' and then combine them using weights w and (1-w). I cannot be sure, but I guess the authors meant one of those two options (which for them turn out to be\r\n equivalent, since they chose w = 0.5).</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "2478810",
      "postDate": "10/12/2023 08:13:13",
      "content": "<p>you can sample new edges and check if they are known already, if not they are likely a negative sample.</p>",
      "rawMarkdown": "you can sample new edges and check if they are known already, if not they are likely a negative sample.",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 11437,
      "author_name": "benhamner",
      "author_url": "",
      "post_date": "06/07/2012 07:21:18",
      "content": "<p>(Igor's message said that he was unable to download the file before he edited the message)</p>\r\n<p>Sorry for the issue. This is a problem that arose in the past, and may be a bug with Chrome, how Azure is serving the files, or our site.</p>\r\n<p>If you have trouble downloading the file, please right click and &quot;Save File As ...&quot; and it should download fine. Alternatively, different browsers should work as well.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 11624,
      "author_name": "helloworld6",
      "author_url": "",
      "post_date": "06/15/2012 02:44:21",
      "content": "<p>Interesting, but I wonder how to choose the negtive sample? as you know, all connections are positive sample.</p>",
      "votes": null,
      "replies": [
        {
          "id": 2478810,
          "author_name": "oliverweissl",
          "author_url": "",
          "post_date": "10/12/2023 08:13:13",
          "content": "<p>you can sample new edges and check if they are known already, if not they are likely a negative sample.</p>",
          "votes": null,
          "replies": []
        }
      ]
    },
    {
      "id": 11627,
      "author_name": "leustagos",
      "author_url": "",
      "post_date": "06/15/2012 18:38:29",
      "content": "<p>This is your opportunity to demonstrate your skills on a real-world social network dataset, and show them your creativity, open-mindedness and tenacity in the face of an open-ended predictive modeling problem! And this time without cheating...</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 11668,
      "author_name": "helloworld6",
      "author_url": "",
      "post_date": "06/17/2012 02:13:01",
      "content": "<p>Sorry, Thanks guys, the same to you.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 11892,
      "author_name": "snoopy0",
      "author_url": "",
      "post_date": "06/26/2012 13:02:48",
      "content": "<p>Got a quick question about the EdgeRank algorithm on pg 1240 of the pdf (not sure if EdgeRank is relevant to this competition or not atm, just asking in general):</p>\r\n<p>Eqn 5: &nbsp;Xn = (1-d)X0 &#43; d(A&#43;wA')Xn-1</p>\r\n<p>1. &nbsp;(A&#43;wA') as a whole must be row normalized? &nbsp;I ran a few quick iterations in Matlab, and the probabilities exploded. &nbsp;Some of them were wayyyy more than one. &nbsp;Row normalization would be equivalent to a uniform probability of chosing each link?</p>\r\n<p>2. &nbsp;I'm a little hazy on why this equation gives the probability of reaching whichever node in n steps. &nbsp;</p>\r\n<p>I understand the (1-d)X0 chunk. &nbsp;Am stuck on the other part which says d(A&#43;wA')Xn-1. &nbsp;If you multiply it out by hand slowly using 1st row as an example, I *think* it says something like &quot;(probability of going from node 1 to node 2)*(probability of being\r\n at node 2) &#43; (probability of going from node 1 to node 3)*(probability of being at node 3).......etc&quot;, and the entire result is supposed to be probability of being at node 1 after n steps??!!??? &nbsp;Why is this?</p>\r\n<p>If the entire (A&#43;wA') matrix were transposed, so that it was (probability of going from node 2 to node 1)*(Prob at node 2)&#43;(prob of going from node 3 to node 1)*(Prob at node 3)&#43;....etc, that would be straightforward to understand. &nbsp;If (A&#43;wA') were symmetric,\r\n it wouldn't matter, but it doesn't have to be...</p>\r\n<p>&nbsp;</p>\r\n<p>It's also *very* possible that I'm just suffering from lack of sleep..LOL. &nbsp;</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 12277,
      "author_name": "omarwugui",
      "author_url": "",
      "post_date": "07/10/2012 19:20:11",
      "content": "<p>&nbsp;</p>\r\n<p style=\"padding-left:30px\">&quot;The training data for the Random Forests was obtained by<br>\r\ncreating eight independent validation sets, each consisting of<br>\r\n4,000 data points (2,000 real edges and 2,000 fake edges).<br>\r\nThese validation sets were constructed to approximate the<br>\r\ndistributions of nodes and edges seen in the test set.&quot;</p>\r\n<p>&nbsp;</p>\r\n<p>What method did you use?<br>\r\n<br>\r\n</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 12288,
      "author_name": "miguel2",
      "author_url": "",
      "post_date": "07/10/2012 23:57:36",
      "content": "<p>Snoopy, it's probably too late to reply to this but I didn't see it before. I also had a look at that paper and was puzzled by eq. 5. It is not correct (or at least, does not correspond with its description), since it does not yield a valid transition matrix.</p>\r\n<p>To fix it, (A&#43;wA') should be <em>column</em> normalized. Alternatively, you could normalize A and A' and then combine them using weights w and (1-w). I cannot be sure, but I guess the authors meant one of those two options (which for them turn out to be\r\n equivalent, since they chose w = 0.5).</p>",
      "votes": null,
      "replies": []
    }
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