{
  "id": 3739,
  "title": "Location Vs. Timezone",
  "url": "/competitions/event-recommendation-engine-challenge/discussion/3739",
  "author_name": "",
  "post_date": "2013-01-31T14:47:48.610Z",
  "votes": null,
  "comment_count": 6,
  "views": 3724,
  "content": "<p>I've been trying to work out some useful features relating to the time at which an event starts. Of course, since all event start-times are in UTC, whereas most users are not in that timezone, it might be useful to adjust to get the start-time *for the user's\r\n timezone*.</p>\r\n<p>However, a quick investigation shows that in a very large number of cases, info in the &quot;location&quot; field (where supplied) seems to disagree wildly with the &quot;timezone&quot; field.</p>\r\n<p>Example: In the training set there are in the order of 20 entries whose location field ends in &quot;United Kingdom&quot;. Of those, 5 have an offset of 60&nbsp;minutes, indicating UTC &#43; 1 hour, which is believable (perhaps the data was taken when Daylight Savings was\r\n in effect). However, there are 10 entries with an offset of 420 minutes, i.e.&nbsp;UTC &#43; 7 hours! (Timezone UTC&#43;7 covers, for example,&nbsp;parts of Indonesia) .The other 5 or so entries cover a wide range of other offset values.</p>\r\n<p>In fact, a quick scan seems to indicate that timezone UTC&#43;7hrs is rather over-represented compared to other offsets - although who knows, perhaps most of the training data relates to users from Indonesia...</p>\r\n<p>I was wondering whether one of the organisers could give some indication of which set of information was more reliable - the &quot;location&quot; field, or the &quot;offset&quot; field. It seems to me that if the&nbsp;location is more reliable&nbsp;, it would be worthwhile investing\r\n some effort in parsing the location and trying to come up with corrections for unlikely timezone values; if the timezone offset is more reliable, however, then unless the timezone field is omitted it's probably best to mostly ignore the location field...</p>",
  "messages": [
    {
      "id": "19892",
      "postDate": "01/31/2013 14:47:48",
      "content": "<p>I've been trying to work out some useful features relating to the time at which an event starts. Of course, since all event start-times are in UTC, whereas most users are not in that timezone, it might be useful to adjust to get the start-time *for the user's\r\n timezone*.</p>\r\n<p>However, a quick investigation shows that in a very large number of cases, info in the &quot;location&quot; field (where supplied) seems to disagree wildly with the &quot;timezone&quot; field.</p>\r\n<p>Example: In the training set there are in the order of 20 entries whose location field ends in &quot;United Kingdom&quot;. Of those, 5 have an offset of 60&nbsp;minutes, indicating UTC &#43; 1 hour, which is believable (perhaps the data was taken when Daylight Savings was\r\n in effect). However, there are 10 entries with an offset of 420 minutes, i.e.&nbsp;UTC &#43; 7 hours! (Timezone UTC&#43;7 covers, for example,&nbsp;parts of Indonesia) .The other 5 or so entries cover a wide range of other offset values.</p>\r\n<p>In fact, a quick scan seems to indicate that timezone UTC&#43;7hrs is rather over-represented compared to other offsets - although who knows, perhaps most of the training data relates to users from Indonesia...</p>\r\n<p>I was wondering whether one of the organisers could give some indication of which set of information was more reliable - the &quot;location&quot; field, or the &quot;offset&quot; field. It seems to me that if the&nbsp;location is more reliable&nbsp;, it would be worthwhile investing\r\n some effort in parsing the location and trying to come up with corrections for unlikely timezone values; if the timezone offset is more reliable, however, then unless the timezone field is omitted it's probably best to mostly ignore the location field...</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "19984",
      "postDate": "02/04/2013 00:17:14",
      "content": "<p>Have you been able to make heads or tails out of the timezone/location issue? I know I tried to by doing string matching in between the location fields in both users and events, but most of the time, I can't do anything because one of the two fields is blank.\r\n Taking the longitude/latitude lines might work, that would require external data--which is ruled out because of the contest rules.</p>\r\n<p>-Brett.</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "20133",
      "postDate": "02/07/2013 11:25:15",
      "content": "<p>I have yet to make any progress on this - although this is at least partly because I've been concentrating on other parts of the data set.</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "20206",
      "postDate": "02/08/2013 22:32:44",
      "content": "<p>Some set of users claim a location that's different from where they currently reside. The timezone is more indicative of their current location, e.g., they are travelling when they last used the product. The &quot;location&quot; is where they either claim to be from\r\n or they haven't kept their location up to date.</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "20389",
      "postDate": "02/12/2013 20:37:54",
      "content": "<p>The rules exclude external data. I would like to be sure on this: are we allowed to use external data (like Yahoo Placemaker API) to convert location strings into coordinates?</p>\r\n<p>Without something like this, event coordinates would be useless.</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "20421",
      "postDate": "02/13/2013 14:12:17",
      "content": "<p>Yes - that is not allowed per my knowledge</p>",
      "rawMarkdown": "",
      "votes": null
    },
    {
      "id": "20464",
      "postDate": "02/14/2013 06:41:49",
      "content": "<p>The rules for this competition disallow external data (which includes the Yahoo Placemaker API), so entries made to this competition should not use any external data.</p>\r\n<p>However, if you find certain external data sources that would potentially be useful, feel free to evaluate them or comment on them (just don't use them to make an entry).</p>",
      "rawMarkdown": "",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 19984,
      "author_name": "brett7",
      "author_url": "",
      "post_date": "02/04/2013 00:17:14",
      "content": "<p>Have you been able to make heads or tails out of the timezone/location issue? I know I tried to by doing string matching in between the location fields in both users and events, but most of the time, I can't do anything because one of the two fields is blank.\r\n Taking the longitude/latitude lines might work, that would require external data--which is ruled out because of the contest rules.</p>\r\n<p>-Brett.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 20133,
      "author_name": "danielhutty",
      "author_url": "",
      "post_date": "02/07/2013 11:25:15",
      "content": "<p>I have yet to make any progress on this - although this is at least partly because I've been concentrating on other parts of the data set.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 20206,
      "author_name": "events4you",
      "author_url": "",
      "post_date": "02/08/2013 22:32:44",
      "content": "<p>Some set of users claim a location that's different from where they currently reside. The timezone is more indicative of their current location, e.g., they are travelling when they last used the product. The &quot;location&quot; is where they either claim to be from\r\n or they haven't kept their location up to date.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 20389,
      "author_name": "aolariu",
      "author_url": "",
      "post_date": "02/12/2013 20:37:54",
      "content": "<p>The rules exclude external data. I would like to be sure on this: are we allowed to use external data (like Yahoo Placemaker API) to convert location strings into coordinates?</p>\r\n<p>Without something like this, event coordinates would be useless.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 20421,
      "author_name": "rkirana",
      "author_url": "",
      "post_date": "02/13/2013 14:12:17",
      "content": "<p>Yes - that is not allowed per my knowledge</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 20464,
      "author_name": "benhamner",
      "author_url": "",
      "post_date": "02/14/2013 06:41:49",
      "content": "<p>The rules for this competition disallow external data (which includes the Yahoo Placemaker API), so entries made to this competition should not use any external data.</p>\r\n<p>However, if you find certain external data sources that would potentially be useful, feel free to evaluate them or comment on them (just don't use them to make an entry).</p>",
      "votes": null,
      "replies": []
    }
  ],
  "raw_markdown_by_id": {
    "19892": "",
    "19984": "",
    "20133": "",
    "20206": "",
    "20389": "",
    "20421": "",
    "20464": ""
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  "source": "meta"
}