track users' movie-watching history and feedback
(Harper and Konstan, 2016). Using the user's movie-
watching history, we formulate a low dimension
continuous emotion vector embedding denotes as the
user emotional vector (uvec). We obtain a user's uvec
embedding value by taking the average of all the
movies' mvecs the user has watched. Note that uvec
may not be unique if two users watched the same set
of movies. The difference between mvec and uvec is
that mvec of a movie is static, with value unchanged
throughout its lifetime.
In contrast, uvec is dynamic, with its value
changes as the user watched and rated a movie. The
advantage of using the dynamic nature of uvec in the
movie recommendation-making process is that we are
taking the most updated user's affective preference
into consideration of the user's decision-making
process. As the user emotional preference change, the
movie recommender will adjust the recommendation-
making process accordingly. We may be the first
party making use of the novelty in leveraging the
dynamic nature of uvec over mvec to enhance the
movie Recommender recommendation-making
process.
Table 1: Affect values, mvec, of movies "The Godfather
(1972)" derived from balanced and unbalanced moods.
Moods
Balanced
Moods
Dataset
Rank
Unbalanced
Moods
Dataset
Rank
Neutral 0.0840931 6 0.04276474 6
Joy 0.059261046 7 0.16501102 3
Sadness 0.08991193 5 0.076094896 4
Hate 0.23262443 1 0.4305178 1
Anger 0.20177138 2 0.1993026 2
Disgust 0.19720455 3 0.053966276 5
Surprise 0.13513364 4 0.03234269 7
Moreover, we can leverage the range and strength
of a film's moods, i.e., mvec, to analyse a film’s
emotional features. In this study, we track six primary
human affective features in emotion: “joy”,
“sadness”, “hate”, “anger”, “disgust”, and “surprise”.
We added "neutral" as the seventh affective feature
for convenience in affective computation. We
normalized the affective features when we compute
mvec for a film. Thus, all affective features in mvec
will add up to one (1). For example, Internet Movie
Database (IMDb) is a popular online movie
information database that has rated “The Godfather
(1972)” as the top movie of all time (IMDb, 2020).
Our emotion detector classified the movie's dominant
affective class as “hate” and depicted the movie's
mvec in Table 1.
2 RELATED WORK
Detecting primary human emotion expression in text
is a relatively new research area in Natural Language
Processing (NLP). A common approach in
identifying the general thought, feeling, or sense in
writing is to classify the contextual polarity
orientation (positive, neutral, and negative) of
opinionated text through the polarity Sentimental
Analysis (SA) (Wilson et al., 2005), and (Maas et al.,
2011). When applying fine-grained Sentiment
Analysis (Fink et al., 2011), researchers can identify
the intensity level of the polarity as a multi-class
single-label classification problem (e.g., very
positive, optimistic, neutral, negative, and very
negative) (Bhowmick et al., 2009). However, to
determine the mental, emotional state or composure
(i.e., mood) in subjective text, Emotional Analysis
(EA) can better suit to handle the task (Tripathi et al.,
2016). The researcher wants to know the writing
feeling under examination is one of the following
primary human emotions or moods.
The study of basic human emotional expressions
started in the era of Aristotle in around 4th century
BC (Konstan and Konstan, 2006). However, not until
Charles Darwin (1872 – 1998) revisited the
investigation of human emotional expression in the
19th century, which propelled the field to its present
stage of modern psychology research (Ekman, 2006).
Paul Ekman et alia in the 1970s developed a Facial
Action Coding System (FACS) to carry out a series
of research on facial expressions that have identified
the following six primary universal human emotions:
happiness, sadness, disgust, fear, surprise, and anger
(Ekman, 1999). Ekman later added contempt as the
seventh primary human emotion to his list (Ekman et
al., 2013). Robert Plutchik invented the Wheel of
Emotions, advocated eight primary emotions: anger,
anticipation, joy, trust, fear, surprise, sadness, and
disgust. Adding to the primary eight emotions are
secondary and complementary emotions for 32
emotions depicted on the initial Wheel of Emotions
(Plutchik, 2001). More recent research by Glasgow
University in 2014 amended that couple pairs of
emotions such as fear and surprise elicited similar
facial muscles response, so are disgust and anger. The
study broke the raw human emotions down to four
fundamental emotions: happiness, sadness,
fear/surprise, and disgust/anger (Tayib and
Jamaludin, 2016).
Like many researchers have based their work on
Ekman’s six primary human emotions (Canales and
Martínez-Barco, 2014), we also focus our emotion
detection and recognition (EDR) on Ekman’s six