{
  "id": 208126,
  "title": "How to include false positives examples in a multi-class classification task in practice? ",
  "url": "/competitions/rfcx-species-audio-detection/discussion/208126",
  "author_name": "",
  "post_date": "2021-01-02T04:57:40.862292Z",
  "votes": 3,
  "comment_count": 3,
  "views": 0,
  "content": "<p>I've been thinking about how to use the false positive data to improve  my classifier, but all I can think is removing the fp from the training data. Is there a way to actually utilize this kind of data in a multi-class classifier? </p>\n<p>I've read this post: <a href=\"https://www.kaggle.com/c/rfcx-species-audio-detection/discussion/200562\" target=\"_blank\">https://www.kaggle.com/c/rfcx-species-audio-detection/discussion/200562</a> and the tip that was given was to \"use them as hard negative examples\", what that actually means and how can I implement it in practice? </p>\n<p>Thanks.</p>",
  "messages": [
    {
      "id": "1135266",
      "postDate": "01/02/2021 04:57:40",
      "content": "<p>I've been thinking about how to use the false positive data to improve  my classifier, but all I can think is removing the fp from the training data. Is there a way to actually utilize this kind of data in a multi-class classifier? </p>\n<p>I've read this post: <a href=\"https://www.kaggle.com/c/rfcx-species-audio-detection/discussion/200562\" target=\"_blank\">https://www.kaggle.com/c/rfcx-species-audio-detection/discussion/200562</a> and the tip that was given was to \"use them as hard negative examples\", what that actually means and how can I implement it in practice? </p>\n<p>Thanks.</p>",
      "rawMarkdown": "I've been thinking about how to use the false positive data to improve  my classifier, but all I can think is removing the fp from the training data. Is there a way to actually utilize this kind of data in a multi-class classifier? \n\nI've read this post: https://www.kaggle.com/c/rfcx-species-audio-detection/discussion/200562 and the tip that was given was to \"use them as hard negative examples\", what that actually means and how can I implement it in practice? \n\nThanks.",
      "votes": null
    },
    {
      "id": "1135509",
      "postDate": "01/02/2021 10:01:30",
      "content": "<p>Hard negatives are tricky samples that models generally struggle to get correct. If you were to (over) sample the false positives during training, your model might be able to learn a better decision boundary. </p>",
      "rawMarkdown": "Hard negatives are tricky samples that models generally struggle to get correct. If you were to (over) sample the false positives during training, your model might be able to learn a better decision boundary.",
      "votes": null
    },
    {
      "id": "1160126",
      "postDate": "01/19/2021 17:21:56",
      "content": "<p>Same question for me, in single-class classification task we can easily use fp sample as negative sample and feed to network to train. But for multi-class classification, shall we label such samples as all 24 zeros and feed to network? Hope someone can help on this.</p>",
      "rawMarkdown": "Same question for me, in single-class classification task we can easily use fp sample as negative sample and feed to network to train. But for multi-class classification, shall we label such samples as all 24 zeros and feed to network? Hope someone can help on this.",
      "votes": null
    },
    {
      "id": "1252505",
      "postDate": "03/25/2021 18:18:30",
      "content": "<p>For anyone interested, there is a way to include false positives in a multi-class classification task, that being, modifying the loss function to accept two different types of representations, for instance, one can represent the classes with hot-one-encodings and use \"1\" or \"0\" to represent that the class is there or not, while the other classes are marked as \"unknown”. There is a great paper in which the authors use this approach: <a href=\"https://www.sciencedirect.com/science/article/abs/pii/S0003682X20304795\" target=\"_blank\">https://www.sciencedirect.com/science/article/abs/pii/S0003682X20304795</a></p>",
      "rawMarkdown": "For anyone interested, there is a way to include false positives in a multi-class classification task, that being, modifying the loss function to accept two different types of representations, for instance, one can represent the classes with hot-one-encodings and use \"1\" or \"0\" to represent that the class is there or not, while the other classes are marked as \"unknown”. There is a great paper in which the authors use this approach: https://www.sciencedirect.com/science/article/abs/pii/S0003682X20304795",
      "votes": null
    }
  ],
  "comments": [
    {
      "id": 1135509,
      "author_name": "reppic",
      "author_url": "",
      "post_date": "01/02/2021 10:01:30",
      "content": "<p>Hard negatives are tricky samples that models generally struggle to get correct. If you were to (over) sample the false positives during training, your model might be able to learn a better decision boundary. </p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 1160126,
      "author_name": "superchenhao",
      "author_url": "",
      "post_date": "01/19/2021 17:21:56",
      "content": "<p>Same question for me, in single-class classification task we can easily use fp sample as negative sample and feed to network to train. But for multi-class classification, shall we label such samples as all 24 zeros and feed to network? Hope someone can help on this.</p>",
      "votes": null,
      "replies": []
    },
    {
      "id": 1252505,
      "author_name": "alefiury",
      "author_url": "",
      "post_date": "03/25/2021 18:18:30",
      "content": "<p>For anyone interested, there is a way to include false positives in a multi-class classification task, that being, modifying the loss function to accept two different types of representations, for instance, one can represent the classes with hot-one-encodings and use \"1\" or \"0\" to represent that the class is there or not, while the other classes are marked as \"unknown”. There is a great paper in which the authors use this approach: <a href=\"https://www.sciencedirect.com/science/article/abs/pii/S0003682X20304795\" target=\"_blank\">https://www.sciencedirect.com/science/article/abs/pii/S0003682X20304795</a></p>",
      "votes": null,
      "replies": []
    }
  ],
  "raw_markdown_by_id": {
    "1135266": "I've been thinking about how to use the false positive data to improve  my classifier, but all I can think is removing the fp from the training data. Is there a way to actually utilize this kind of data in a multi-class classifier? \n\nI've read this post: https://www.kaggle.com/c/rfcx-species-audio-detection/discussion/200562 and the tip that was given was to \"use them as hard negative examples\", what that actually means and how can I implement it in practice? \n\nThanks.",
    "1135509": "Hard negatives are tricky samples that models generally struggle to get correct. If you were to (over) sample the false positives during training, your model might be able to learn a better decision boundary.",
    "1160126": "Same question for me, in single-class classification task we can easily use fp sample as negative sample and feed to network to train. But for multi-class classification, shall we label such samples as all 24 zeros and feed to network? Hope someone can help on this.",
    "1252505": "For anyone interested, there is a way to include false positives in a multi-class classification task, that being, modifying the loss function to accept two different types of representations, for instance, one can represent the classes with hot-one-encodings and use \"1\" or \"0\" to represent that the class is there or not, while the other classes are marked as \"unknown”. There is a great paper in which the authors use this approach: https://www.sciencedirect.com/science/article/abs/pii/S0003682X20304795"
  },
  "source": "meta"
}