DUCK 謠言檢測《DUCK: Rumour Detection on Social Media by Modelling User and Comment Propagation Networks》( 三 )


  • Q3 [User tree]: Can social relations help modelling the user network?
  • Q4 [Overall performance]: Do the three different components complement each other and how does a combined approach compared to existing rumour detection systems?
  • 4.2.1 Comment Tree為了理解使用BERT處理一對 parent-child posts 的影響 , 我們提出了另一種替代方法(“unpaired”),即使用 BERT 獨立處理每個帖子,然后將其 [CLS] 表示提供給GAT 。
    $h_{p}=\operatorname{BERT}\left(\operatorname{emb}\left([C L S], c_{p}\right)\right)$
    其中,$h$ 將用作 GAT 中的初始節點表示($h^{(0)}$) 。這里報告了這個替代模型(“unpaired”)及不同的聚合方法(“root”、“?root”、“$\bigtriangleup $” 和 “all”)的性能 。
    DUCK 謠言檢測《DUCK: Rumour Detection on Social Media by Modelling User and Comment Propagation Networks》

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    Comparing the aggregation methods, "all" performs the best, followed by "$\boldsymbol{\Delta}$ " and "root" (0.88  vs  . 0.87 vs. 0.86 in Twitter16; 0.87 vs. 0.86 vs. 0.85 in CoAID in terms of Macro-F1). We can see that the root and its immediate neighbours contain most of the information, and not including the root node impacts the performance severely (both Twitter16 and CoAID drops to 0.80 with $\neg$ root).
    Does processing the parent-child posts together with BERT help? The answer is evidently yes, as we see a substantial drop in performance when we process the posts independently: "unpaired" produces a macro-F1 of only 0.83 in both Twitter16 and CoAID. Given these results, our full model (DUCK) will be using "all"' as the aggregation method for computing the comment graph representation.
    4.2.2 Comment ChainFig. 3 繪制了我們改變所包含的評論數量來回答 Q2 的結果:
    DUCK 謠言檢測《DUCK: Rumour Detection on Social Media by Modelling User and Comment Propagation Networks》

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    4.2.3 User Tree
    DUCK 謠言檢測《DUCK: Rumour Detection on Social Media by Modelling User and Comment Propagation Networks》

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    4.2.4 Overall Rumour Detection Performance
    DUCK 謠言檢測《DUCK: Rumour Detection on Social Media by Modelling User and Comment Propagation Networks》

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    【DUCK 謠言檢測《DUCK: Rumour Detection on Social Media by Modelling User and Comment Propagation Networks》】

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