# Prediction of Eudaimonic and Hedonic Orientation of Movie Watchers
## 2 Related Work
### Personality Research from Psychology  
As mentioned earlier, psychology research defines personality traits as the _most important ways in which individuals differ in their enduring emotional, interpersonal, experiential, attitudinal and motivational styles_[1]. In order to account for the diversity of users, several personality models have been devised. Over the past few decades, factor analysis has been used to reduce personality traits to their underlying factors [16; 17; 18].  
Several independent researchers have contributed to this research line by introducing various factors. The most known is the Five Factor Model (FFM), which is composed of the factors Openness, Conscientiousness, Extraversion, Agreeableness and Neuroticism. The model is based on the lexical hypothesis, i.e., the things that are important eventually end up in words we use. Studying the usage of language, the FFM was constructed [1].  
The FFM is not the only personality model that has been used by researchers but it is the most extensively used. There are other alternative models with different numbers of factors that were introduced to argue for the comprehensibility of FFM. For example, the HEXACO model is an alternative personality model that includes six factors. The sixth factor in this model is called Honesty-Humility [19].  
Although the FFM is an established model, it does not necessarily fit into specific domains. For this reason, several domain-specific models have been developed. In the domain of human resources, the RIASEC model, composed of the types realistic, investigative, artistic, social, enterprising and conventional is used [11]. These types are correlated with the FFM factors but account for more fine-grained variance in the job domain and also offer more explanational power.  
For explaining the behavior of users in groups, the Thomas-Kilman model has been proposed [12]. This model has two factors, assertiveness and cooperativeness, that account for how people cope in conflict situations. The usage of the Thomas-Kilman model has been investigated in the domain of group recommender systems [20; 21]. As an example, a recent work done by [PERSON] et al. [21] proposed a group recommendation approach that takes the users' personality into account [21].  
They modeled the influence of users on other group members using influence graphs in which nodes represent users and edges represent users' influence on other group members. Their proposed model suggested that a user's influence on another member would be stronger if they are more assertive and less cooperative when the other members are less assertive and more cooperative.  
Further domain-specific models include the Bartle gaming types, which distinguishes killers, achievers, explorers and socializers [10], and in particular, the eudaimonic and hedonic orientation (EHO) model, which is the topic of prediction of this paper.  
The EHO model has roots in positive psychology [22]. Human experiences have been modeled using the concepts of eudaimonia and hedonia [23]. The eudaimonic experience is composed of two factors: (i) deeper reflection, which encompasses relatedness, central values and personal growth; and (ii) life evaluation, which encompasses the purpose of life, self-acceptance and autonomy.  
The hedonic experience, on the other hand, is about pure pleasure. The two factors have a low correlation, which indicates their almost-orthogonality. The work of [PERSON] and [PERSON] showed that users have different propensities for eudaimonic and hedonic experiences, which leads to the concept of traits in the EHO model [13]. Furthermore, they devised an instrument for measuring the EHO factors of users in the domain of movie consumption [13]. This questionnaire has six questions for the eudaimonic orientation (EO) and six questions for the hedonic orientation (HO).