{
  "id": 453158,
  "title": "In this challenge, do ensemble can increase score?",
  "url": "/competitions/UBC-OCEAN/discussion/453158",
  "author_name": "Quan Vu",
  "post_date": "2023-11-05T07:23:29.080000",
  "votes": 3,
  "comment_count": 16,
  "views": 0,
  "content": "<p>I split data to 5 fold, submission is ensemble by 5 fold model. Another submission, I ensemble 5 fold model 1 and 5 fold model 2. But score not improve, this is very weird. Does anyone have the same problem as me?</p>",
  "messages": [
    {
      "id": 2513103,
      "postDate": "2023-11-05T07:23:29.080Z",
      "content": "<p>I split data to 5 fold, submission is ensemble by 5 fold model. Another submission, I ensemble 5 fold model 1 and 5 fold model 2. But score not improve, this is very weird. Does anyone have the same problem as me?</p>",
      "rawMarkdown": "I split data to 5 fold, submission is ensemble by 5 fold model. Another submission, I ensemble 5 fold model 1 and 5 fold model 2. But score not improve, this is very weird. Does anyone have the same problem as me?",
      "votes": 3
    },
    {
      "id": 2513294,
      "postDate": "2023-11-05T11:13:10.783Z",
      "content": "<p>Same problem, I ensembled the model that got 0.4 and the model that got 0.38, and got 0.38. We need to reconsider how we use softmax in ensemble.</p>",
      "rawMarkdown": "Same problem, I ensembled the model that got 0.4 and the model that got 0.38, and got 0.38. We need to reconsider how we use softmax in ensemble.",
      "votes": 1,
      "replies": [
        {
          "id": 2513437,
          "postDate": "2023-11-05T12:51:41.787Z",
          "content": "<p>I ensemble 5 fold 0.36; 0.38; 0.36; 0.34; 0.4 -&gt; ensemble LB score = 0.4. Ensemble 5 fold LB = 0.43 with 5 fold LB = 0.45 -&gt; ensemble LB score = 0.45 😅</p>",
          "rawMarkdown": "I ensemble 5 fold 0.36; 0.38; 0.36; 0.34; 0.4 -> ensemble LB score = 0.4. Ensemble 5 fold LB = 0.43 with 5 fold LB = 0.45 -> ensemble LB score = 0.45 😅",
          "replies": [
            {
              "id": 2513455,
              "postDate": "2023-11-05T13:11:05.763Z",
              "content": "<p>The scores 0.36; 0.38; 0.36; 0.34; 0.4, do you compute them on all images or just on TMA?</p>",
              "rawMarkdown": "The scores 0.36; 0.38; 0.36; 0.34; 0.4, do you compute them on all images or just on TMA?"
            },
            {
              "id": 2513533,
              "postDate": "2023-11-05T14:16:07.807Z",
              "content": "<p>All image on public leader board.</p>",
              "rawMarkdown": "All image on public leader board."
            },
            {
              "id": 2556843,
              "postDate": "2023-12-11T03:28:17.843Z",
              "content": "<p>Has this problem been solved</p>",
              "rawMarkdown": "Has this problem been solved"
            },
            {
              "id": 2557857,
              "postDate": "2023-12-11T17:45:08.670Z",
              "content": "<p>No, this problem not solved. My ensemble model score lower or equal best single model.</p>",
              "rawMarkdown": "No, this problem not solved. My ensemble model score lower or equal best single model."
            }
          ]
        }
      ]
    },
    {
      "id": 2513225,
      "postDate": "2023-11-05T09:50:29Z",
      "content": "<p>yes same problem ensemble decreases the score</p>",
      "rawMarkdown": "yes same problem ensemble decreases the score",
      "votes": 1
    },
    {
      "id": 2513334,
      "postDate": "2023-11-05T11:40:10.103Z",
      "content": "<p>Same here. Also, sometimes I have a new model that has better local validation/CV score, but then the LB score is worst… how are you evaluating whether a model will be better or no? Any ideas?..</p>",
      "rawMarkdown": "Same here. Also, sometimes I have a new model that has better local validation/CV score, but then the LB score is worst... how are you evaluating whether a model will be better or no? Any ideas?..",
      "votes": 2,
      "replies": [
        {
          "id": 2513338,
          "postDate": "2023-11-05T11:42:26.373Z",
          "content": "<p>Does 'better local validation/CV score' means only of TMA scores?</p>",
          "rawMarkdown": "Does 'better local validation/CV score' means only of TMA scores?",
          "replies": [
            {
              "id": 2513355,
              "postDate": "2023-11-05T11:50:57.543Z",
              "content": "<p>No, of all the images. Are you checking the score just on TMA to evaluate whether a model is better than another?</p>",
              "rawMarkdown": "No, of all the images. Are you checking the score just on TMA to evaluate whether a model is better than another?"
            },
            {
              "id": 2513360,
              "postDate": "2023-11-05T11:56:36.373Z",
              "content": "<p>Yes, but there are only 25 TMA images, the scores  hard to trust. <br>\nSo, I observe whether the accuracy of the WSI image of validation also increases.</p>",
              "rawMarkdown": "Yes, but there are only 25 TMA images, the scores  hard to trust. \nSo, I observe whether the accuracy of the WSI image of validation also increases."
            },
            {
              "id": 2513390,
              "postDate": "2023-11-05T12:22:57.680Z",
              "content": "<p>You mean if \"the accuracy of the WSI image of validation also decreases\"?. So it is not yet clear to me: do  you check the validation score on the whole TMA+WSI images or just the TMA score?</p>",
              "rawMarkdown": "You mean if \"the accuracy of the WSI image of validation also decreases\"?. So it is not yet clear to me: do  you check the validation score on the whole TMA+WSI images or just the TMA score?"
            },
            {
              "id": 2513449,
              "postDate": "2023-11-05T13:07:06.710Z",
              "content": "<p>No, I check two validation datasets. (20% WSI and 25 TMA images)</p>",
              "rawMarkdown": "No, I check two validation datasets. (20% WSI and 25 TMA images)",
              "votes": 1
            },
            {
              "id": 2513466,
              "postDate": "2023-11-05T13:18:46.530Z",
              "content": "<p>But then If you use all TMA images for validation, you don't have any of these in the training set? I assume then for submission you retrain with all of them not to loose that valuable information, right?</p>",
              "rawMarkdown": "But then If you use all TMA images for validation, you don't have any of these in the training set? I assume then for submission you retrain with all of them not to loose that valuable information, right?"
            },
            {
              "id": 2513475,
              "postDate": "2023-11-05T13:23:43.013Z",
              "content": "<p>Yes, I am now checking whether my strategy works well for TMA and will eventually use it for Training.</p>",
              "rawMarkdown": "Yes, I am now checking whether my strategy works well for TMA and will eventually use it for Training."
            }
          ]
        },
        {
          "id": 2513432,
          "postDate": "2023-11-05T12:48:07.730Z",
          "content": "<p>😂 Some time, my CV increase but LB decrease, some ensemble model have better CV but LB = 0.3 😅. The most confusing thing is ensemble cannot improve LB score. I think my code is bug, but i cannot found it 😅</p>",
          "rawMarkdown": "😂 Some time, my CV increase but LB decrease, some ensemble model have better CV but LB = 0.3 😅. The most confusing thing is ensemble cannot improve LB score. I think my code is bug, but i cannot found it 😅",
          "votes": 1
        }
      ]
    }
  ],
  "comments": [
    {
      "id": 2513294,
      "author_name": "devchopin",
      "author_url": "",
      "post_date": "2023-11-05T11:13:10.783000",
      "content": "<p>Same problem, I ensembled the model that got 0.4 and the model that got 0.38, and got 0.38. We need to reconsider how we use softmax in ensemble.</p>",
      "votes": 1,
      "replies": [
        {
          "id": 2513437,
          "author_name": "Quan Vu",
          "author_url": "",
          "post_date": "2023-11-05T12:51:41.787000",
          "content": "<p>I ensemble 5 fold 0.36; 0.38; 0.36; 0.34; 0.4 -&gt; ensemble LB score = 0.4. Ensemble 5 fold LB = 0.43 with 5 fold LB = 0.45 -&gt; ensemble LB score = 0.45 😅</p>",
          "votes": 0,
          "replies": [
            {
              "id": 2513455,
              "author_name": "Andreu Arderiu",
              "author_url": "",
              "post_date": "2023-11-05T13:11:05.763000",
              "content": "<p>The scores 0.36; 0.38; 0.36; 0.34; 0.4, do you compute them on all images or just on TMA?</p>",
              "votes": 0,
              "replies": []
            },
            {
              "id": 2513533,
              "author_name": "Quan Vu",
              "author_url": "",
              "post_date": "2023-11-05T14:16:07.807000",
              "content": "<p>All image on public leader board.</p>",
              "votes": 0,
              "replies": []
            },
            {
              "id": 2556843,
              "author_name": "allen wang",
              "author_url": "",
              "post_date": "2023-12-11T03:28:17.843000",
              "content": "<p>Has this problem been solved</p>",
              "votes": 0,
              "replies": []
            },
            {
              "id": 2557857,
              "author_name": "Quan Vu",
              "author_url": "",
              "post_date": "2023-12-11T17:45:08.670000",
              "content": "<p>No, this problem not solved. My ensemble model score lower or equal best single model.</p>",
              "votes": 0,
              "replies": []
            }
          ]
        }
      ]
    },
    {
      "id": 2513225,
      "author_name": "Arunodhayan",
      "author_url": "",
      "post_date": "2023-11-05T09:50:29",
      "content": "<p>yes same problem ensemble decreases the score</p>",
      "votes": 1,
      "replies": []
    },
    {
      "id": 2513334,
      "author_name": "Andreu Arderiu",
      "author_url": "",
      "post_date": "2023-11-05T11:40:10.103000",
      "content": "<p>Same here. Also, sometimes I have a new model that has better local validation/CV score, but then the LB score is worst… how are you evaluating whether a model will be better or no? Any ideas?..</p>",
      "votes": 2,
      "replies": [
        {
          "id": 2513338,
          "author_name": "devchopin",
          "author_url": "",
          "post_date": "2023-11-05T11:42:26.373000",
          "content": "<p>Does 'better local validation/CV score' means only of TMA scores?</p>",
          "votes": 0,
          "replies": [
            {
              "id": 2513355,
              "author_name": "Andreu Arderiu",
              "author_url": "",
              "post_date": "2023-11-05T11:50:57.543000",
              "content": "<p>No, of all the images. Are you checking the score just on TMA to evaluate whether a model is better than another?</p>",
              "votes": 0,
              "replies": []
            },
            {
              "id": 2513360,
              "author_name": "devchopin",
              "author_url": "",
              "post_date": "2023-11-05T11:56:36.373000",
              "content": "<p>Yes, but there are only 25 TMA images, the scores  hard to trust. <br>\nSo, I observe whether the accuracy of the WSI image of validation also increases.</p>",
              "votes": 0,
              "replies": []
            },
            {
              "id": 2513390,
              "author_name": "Andreu Arderiu",
              "author_url": "",
              "post_date": "2023-11-05T12:22:57.680000",
              "content": "<p>You mean if \"the accuracy of the WSI image of validation also decreases\"?. So it is not yet clear to me: do  you check the validation score on the whole TMA+WSI images or just the TMA score?</p>",
              "votes": 0,
              "replies": []
            },
            {
              "id": 2513449,
              "author_name": "devchopin",
              "author_url": "",
              "post_date": "2023-11-05T13:07:06.710000",
              "content": "<p>No, I check two validation datasets. (20% WSI and 25 TMA images)</p>",
              "votes": 1,
              "replies": []
            },
            {
              "id": 2513466,
              "author_name": "Andreu Arderiu",
              "author_url": "",
              "post_date": "2023-11-05T13:18:46.530000",
              "content": "<p>But then If you use all TMA images for validation, you don't have any of these in the training set? I assume then for submission you retrain with all of them not to loose that valuable information, right?</p>",
              "votes": 0,
              "replies": []
            },
            {
              "id": 2513475,
              "author_name": "devchopin",
              "author_url": "",
              "post_date": "2023-11-05T13:23:43.013000",
              "content": "<p>Yes, I am now checking whether my strategy works well for TMA and will eventually use it for Training.</p>",
              "votes": 0,
              "replies": []
            }
          ]
        },
        {
          "id": 2513432,
          "author_name": "Quan Vu",
          "author_url": "",
          "post_date": "2023-11-05T12:48:07.730000",
          "content": "<p>😂 Some time, my CV increase but LB decrease, some ensemble model have better CV but LB = 0.3 😅. The most confusing thing is ensemble cannot improve LB score. I think my code is bug, but i cannot found it 😅</p>",
          "votes": 1,
          "replies": []
        }
      ]
    }
  ],
  "raw_markdown_by_id": {
    "2513103": "I split data to 5 fold, submission is ensemble by 5 fold model. Another submission, I ensemble 5 fold model 1 and 5 fold model 2. But score not improve, this is very weird. Does anyone have the same problem as me?",
    "2513294": "Same problem, I ensembled the model that got 0.4 and the model that got 0.38, and got 0.38. We need to reconsider how we use softmax in ensemble.",
    "2513225": "yes same problem ensemble decreases the score",
    "2513334": "Same here. Also, sometimes I have a new model that has better local validation/CV score, but then the LB score is worst... how are you evaluating whether a model will be better or no? Any ideas?.."
  }
}