The term emotion analysis in text subsumes various natural language processing tasks which have in common the goal to enable computers to understand emotions. Most popular is emotion classification in which one or multiple emotions are assigned to a predefined textual unit. While such setting is appropriate for identifying the reader's or author's emotion, emotion role labeling adds the perspective of mentioned entities and extracts text spans that correspond to the emotion cause. The underlying emotion theories agree on one important point; that an emotion is caused by some internal or external event and comprises several subcomponents, including the subjective feeling and a cognitive evaluation. We therefore argue that emotions and events are related in two ways. (1) Emotions are events; and this perspective is the fundament in natural language processing for emotion role labeling. (2) Emotions are caused by events; a perspective that is made explicit with research how to incorporate psychological appraisal theories in NLP models to interpret events. These two research directions, role labeling and (event-focused) emotion classification, have by and large been tackled separately. In this paper, we contextualize both perspectives and discuss open research questions.

翻译：文本中的情感分析涵盖了多种自然语言处理任务，其共同目标是使计算机能够理解情感。最普遍的是情感分类任务，它将一个或多个情感标签分配给预定义的文本单元。虽然这种设定适用于识别读者或作者的情感，但情感角色标注增加了从实体视角出发的分析维度，并提取与情感原因相对应的文本片段。基础情感理论在一个关键点上达成共识：情感由某些内部或外部事件引发，并包含多个子成分，包括主观感受和认知评价。因此，我们认为情感与事件存在双重关联：（1）情感本身就是事件——这一视角构成了自然语言处理中情感角色标注的理论基础；（2）情感由事件引发——这一视角通过研究如何将心理评价理论融入自然语言处理模型来解释事件而得以显性化。这两大研究方向——角色标注与（面向事件的）情感分类——长期以来基本独立发展。本文旨在厘清两种视角间的联系，并探讨尚未解决的关键研究问题。