As massive conversation examples are easily accessible on the Internet, we are now able to organize large-scale conversation corpora to build chatbots in a data-driven manner. Multi-modal social chatbots produce conversational utterances according to both textual utterances and vision signals. Due to the difficulty of bridging different modalities, the dialogue generation model of chatbots falls into local minima that only capture the mapping between textual input and textual output, as a result, it almost ignores the non-textual signals. Further, similar to the dialogue model with plain text as input and output, the generated responses from multi-modal dialogue also lack diversity and informativeness. In this paper, to address the above issues, we propose a Multi-View Meta-Learning (MultiVML) algorithm that groups samples in multiple views and customizes generation models to different groups. We employ a multi-view clustering to group the training samples so as to attend more to the unique information in non-textual modality. Tailoring different sets of model parameters for each group boosts the genereation diversity via meta-learning. We evaluate MultiVML on two variants of the OpenViDial benchmark datasets. The experiments show that our model not only better explore the information from multiple modalities, but also excels baselines in both quality and diversity.

Sarcasm is a sophisticated expression, commonly used on social media, e.g., Reddit and Twitter. The presence of sarcasm in social media text flips the polarity of sentiment, thus hindering the performance of works that require true sentiment, e.g., sentiment analysis and opinion mining. However, current works fail to exploit commonsense knowledge in the sarcasm detection task. In this paper, we revisit sarcasm detection from a novel perspective, which models commonsense knowledge as well as context semantics to reason with sarcasm. More specifically, we propose a commonsense-aware model with a heterogeneous graph attention network that leverages commonsense knowledge, enabling it to better understand implied sentiment behind the literal meaning. We conduct experiments on benchmark datasets from Reddit and Internet Argument Corpus. Experimental results show that our proposed approach yields superior performance with commonsense knowledge integrated.

The rapid development of social media makes it easy for people to acquire information while also providing a platform for publishing and spreading fake news. Fake news brings plenty of explicit and implicit risks to social stability, making fake news detection an issue that deserves attention. Recent methods based on graph neural networks (GNN) achieve impressive results in fake news detection, but their performance is still limited in practice due to the absence of high-order relations between nodes. In this paper, we propose a Sentiment-Aware Hypergraph Attention Network (SA-HyperGAT) for fake news detection. SA-HyperGAT can better leverage different kinds of information from news contents and user comments with hypergraphs, which can capture higher-order dependency between words and sentences compared with general graphs. Specifically, we first construct two hypergraphs with distinct types of nodes and hyperedges to utilize structural information of news contents and sentimental information of user comments. Then we adopt a hypergraph attention network with a dual attention mechanism to learn the composed representations of two hypergraphs for the final prediction. Our proposed SA-HyperGAT outperforms competitive baselines on two real-world datasets. Extensive experimental results prove the effectiveness of each component in SA-HyperGAT.

In recent years, online social networks (OSNs) have undoubtedly become the most popular information diffusion channel. However, existing work has rarely focused on the end-to-end diffusion path, which means information diffusion between user pairs is still a problem unresolved. In this paper, an end-to-end independent cascade model (EICM) is proposed. Then, we present an efficient approach called end-to-end diffusion flow pruning (EDFP) that simplify large-scale social networks until main diffusion paths of end-to-end networks are identified.