它考虑的是一个人利用这种情况的能力。知觉与评价中介是评价理论的基本要素。感知被定义为环境和个体的个人观点。评价过程是根据一定的变量对感知环境进行评价的过程。中介是人的情感与人的评价价值之间发展关系的过程(Liu, 2012)。通过评价建立的过程模型，详细描述了评价在社会中实际发生的认知价值、机制和动态。有一种认知方法被用来理解人的情感。近年来，评价理论的概念发生了革命性的变化(Liu, and Zhang, 2012)。人们发现，像twitter这样的社交媒体的出现，已经在这一过程中造成了重大的变化。
From reading Malcolm Turnbull tweets, it can be understood that there is a overall positive aura or vibration that tends to become neutral emphasis to express information to the people. Turnbull also uses catch phrases and tries to joke around when discussing about important subjects. On reading about Bull Shorten tweets, there is important given to the issues regarding climate. He also expresses that the government is indulging in wasteful spending. There is excessive criticism of the ruling government and discussion of personal efforts to connect with the community. This is the overall impact audience can get from reading the tweets posted by the leaders of these political parties. Sentiment analysis for these leaders has been elucidated in detail in the following.The theoretical models of appraisal theory and the social media appraisal techniques are probed in detail in the following.Appraisal theory states about the significance of an event in relation to a person including whether it would be threat or opportunity for the individuals.
It considers the ability of the person to take advantage of the situation. Perception and appraisal mediation are the elements of the appraisal theory. Perception is defined as the environment and the personal viewpoints of the individuals. Appraisal process is the process that evaluates the perceived environment with respect to certain variables. Mediation is the process by which there is a relationship that is developed by persons’ emotions to the appraisal values of the person (Liu, 2012). A process model that has been developed by appraisal described in detail the value of the cognition, mechanisms and dynamic of how the appraisal actually happens in the society. There is a cognitive approach that has been used to understand about the emotions of the person. The notions of appraisal theory have been revolutionized in recent times (Liu, and Zhang, 2012). It has been found that the advent of social media such as twitter has caused a significant change in the processes.