2013) further highlights the challenging nature of
understanding what triggers an emotion.
In this work we take a novel view, and formulate
emotion-trigger detection as an abstractive summa-
rization task that synthesizes a natural language
description of the events and their appraisals that
trigger a particular emotion. We frame our work
as emotion detection and trigger summarization
(Figure 1), which entails both detecting perceived
emotions in text, and summarizing triggers for each
emotion.
We present COVIDET (
E
motions and their
T
riggers during
Covid
-19), a new dataset sourced
from
1,883
English Reddit posts about the COVID-
19 pandemic. Each post is annotated with 7 fine-
grained emotion labels; for each emotion, annota-
tors provided a concise, abstractive summary de-
scribing the triggers of the emotion. The triggers
are further validated in a separate stage. COVIDET
spans from June 2021 to January 2022, captur-
ing various significant events as well as how they
were emotionally appraised during the pandemic.
Compared to prior emotion studies that consider
only sentence-level texts (Sosea and Caragea,2020;
Demszky et al.,2020) or (short) tweets (Sosea et al.,
2022;Abdul-Mageed and Ungar,2017), COVIDET
is challenging as it contains significantly longer
texts. We showcase examples of COVIDET in Ap-
pendix §A.
Analyses of COVIDET reveal that negative emo-
tions such as fear and anger are prevalent. These
emotions co-occur most frequently with anticipa-
tion, which consistently rise after the Omicron sub-
variant became more dominant with fear dropping.
Topic modeling over the trigger summaries points
to irritations toward those who don’t mask or get
vaccinated, and positivity towards the vaccines.
Using COVIDET, we benchmark models for
emotion detection and emotion-trigger summariza-
tion. We employ both separate emotion detection
and trigger summarization models, as well as joint
models that we designed to simultaneously detect
emotions and generate trigger summaries. Our ex-
periments showcase the distinct nature of our task,
emphasizing that COVIDET is vital to training re-
liable emotion detection and trigger summariza-
tion approaches in a Covid-19 context. COVIDET
bears various unique characteristics, ranging from
its long sequences and invaluable context to the na-
ture of the task itself. Therefore, general emotion
detection or summarization models unsurprisingly
lag behind in performance compared to our meth-
ods. Moreover, human evaluation of the generated
trigger summaries tailored for emotion-trigger sum-
marization indicates that our models are effective
in capturing the underlying triggers of the post.
We release COVIDET and our code at
https:
//github.com/honglizhan/CovidET.
2 Related Work
Summarization.
Recent pre-trained models led
to substantial progress in single document summa-
rization. In the case of abstractive summarization,
encoder-decoder transformer models are used to
synthesize a concise description of the most salient
concepts in the input (Lewis et al.,2020;Zhang
et al.,2020). Significant efforts in summarization
focus on news because of the availability of large
datasets such as CNN/DailyMail (Hermann et al.,
2015) and XSum (Narayan et al.,2018); in the do-
main of social media, TL;DR sentences has been
mined in Reddit to serve as summaries and train
models (Völske et al.,2017;Kim et al.,2019).
However, generic summaries tend not to be infor-
mative if users are concerned with specific emo-
tions expressed.
In this sense our setup fits into settings where
only a certain part of the content is of interest to the
user. We could view our task as answering a query,
“Why does the writer feel [emotion]?”. However,
such queries are more general than query-based
summarization (Daumé III and Marcu,2006;Otter-
bacher et al.,2009;Schilder and Kondadadi,2008;
Nema et al.,2017;Baumel et al.,2018;Laskar
et al.,2020;Su et al.,2021;Zhong et al.,2021),
where queries tend to be more document-specific.
Perhaps a closer task is opinion summarization, or
aspect-based summarization more generally. In
opinion summarization, models need to summarize
affect/opinions about a certain aspect of a service or
product (Popescu and Etzioni,2005;Angelidis and
Lapata,2018;Huy Tien et al.,2019;Suhara et al.,
2020;Angelidis et al.,2021;Amplayo and Lapata,
2021); on the contrary, our setup entails identify-
ing the emotions and summarizing the events and
how they were made sense of with respect to each
emotion. In aspect-based summarization, existing
work has explored summarizing with respect to pre-
designated aspects of certain news (Frermann and
Klementiev,2019;Ahuja et al.,2022), and entities
mentioned in text (Maddela et al.,2022).