Second, previous studies generally follow two
research directions to model user history, i.e., se-
quence and graph modeling. Formulating user his-
tory as a sequence of user’s clicked news is a more
prevalent direction, based on which time-sequential
models (Okura et al.,2017;An et al.,2019;Qi et al.,
2021b) and attentive models (Zhu et al.,2019;Wu
et al.,2019a,b,d;Qi et al.,2021a,c) are proposed.
Besides, graph modeling is proved effective for rec-
ommender systems (Chen et al.,2020). Ge et al.
(2020) and Hu et al. (2020b) formulate news and
users jointly in a bipartite graph to model news-
user interaction. However, since most candidate
news in test data has no existing interaction with
users (i.e., cold-news), the isolated cold-news nodes
cause this bipartite graph modeling degenerate. Re-
cent works formulate user history as heterogeneous
graphs and employ advanced graph learning meth-
ods to extract the user-graph representations (Hu
et al.,2020a;Mao et al.,2021;Wu et al.,2021).
These works focus on how to extract fine-grained
representations from the user-graph side but neglect
necessary feature interaction between the candidate
news and user-graphs.
In this work, we propose
D
ual-
I
nteractive
G
raph
AT
tention networks (DIGAT) to address the afore-
mentioned limitations. DIGAT consists of news-
and user-graph channels to encode the candidate
news and user history, respectively. In the news-
graph channel, we introduce semantic-augmented
graph (SAG) modeling to enrich the semantic repre-
sentation of the single candidate news. In SAG, the
original candidate news is regarded as the root node,
while the semantic-relevant news documents are
represented as the extended nodes to augment the
semantics of the candidate news. We integrate the
local and global contexts of SAG as the semantic-
augmented candidate news representations.
In the user-graph channel, motivated by Mao
et al. (2021) and Wu et al. (2021), we model user
history with a news-topic graph to represent multi-
levels of user interests. Most notably, we design a
dual-graph interaction process to learn news- and
user-graph representations with effective feature
interaction. Different from the individual graph
attention network (Veliˇ
ckovi´
c et al.,2018), DIGAT
updates news and user graph embeddings with the
interactive attention mechanism. Particularly, in
each layer of the dual-graph, the user (news) graph
context is incorporated into its dual news (user)
node embedding learning iteratively.
Extensive experiments on the benchmark dataset
MIND (Wu et al.,2020) show that DIGAT signifi-
cantly outperforms the existing news recommenda-
tion methods. Further ablation studies and analyses
confirm that semantic-augmented news graph mod-
eling and dual-graph interaction can substantially
improve news recommendation performance.
2 Related Work
Personalized news recommendation is important to
online news services (Okura et al.,2017;Yi et al.,
2021). Existing neural news recommendation meth-
ods typically aim to learn informative news and
user representations (Wang et al.,2018;Zhu et al.,
2019;An et al.,2019;Wu et al.,2019a,b,d;Liu
et al.,2020;Wang et al.,2020;Qi et al.,2021a,b,c;
Wu et al.,2021;Li et al.,2022). For example,
An et al. (2019) used a CNN network to extract
textual representations from news titles and used
a GRU network to learn short-term user interests
combined with long-term user embeddings. The
matching probabilities between candidate news and
users are computed over the learned news and user
representations. Wu et al. (2019d) utilized multi-
head self-attention networks to learn informative
news and user representations from news titles and
user clicked history. These methods regarded the
single candidate news as the input to news encoder,
which may not contain sufficient semantics to rep-
resent a user-interested news topic. Different from
these methods, we encode the candidate news with
semantic-augmented graphs to enrich its semantic
representations. More recently, graph-based meth-
ods were proposed for news recommendation (Ge
et al.,2020;Hu et al.,2020a,b;Mao et al.,2021;
Wu et al.,2021). For example, Wu et al. (2021)
proposed a heterogeneous graph pooling method
to learn fine-grained user representations. How-
ever, feature interaction between candidate news
and users is inadequate or neglected in these meth-
ods. In contrast, our approach models effective
feature interaction between news and user graphs
for accurate news-user representation matching.
3 Approach
Problem Formulation.
Denote the clicked-news
history of a user
u
as
Hu= [n1, n2, ..., n|H|]
, con-
taining
|H|
clicked news items. For the news
n
, its
textual content consists of a sequence of
|T|
words
as
Tn= [w1, w2, ..., w|T|]
. Based on
Hu
and
Tn
,
the goal of news recommendation is to predict the