# Applying Recommender Systems to Predict Personalized Film Age Ratings for Parents
## 2 Related Work
### Film Age Rating Systems  
Film age rating systems are used worldwide to provide guidance on the suitability of films for different age groups. These systems are generally established by governments or independent organizations and generally differ from country to country, based on cultural norms and concerns about media content. In the following, we provide a brief summary of some major film age rating systems.  
* The MPLA (Motion Picture Association of America) was established in the USA. The MPLA is one of the most well-known film classification systems and has been in use since 1968 [8]. Its key ratings include the following
* \(G\) (General Audience): Suitable for all ages.
* \(PG\) (Parental Guidance): Some material may not be suitable for children.
* \(PG\)-13: Parents are strongly advised that some content may be inappropriate for children under 13 years of age.
* \(R\) (Restricted): Viewers under 17 years of age require an accompanying adult.
* NC-17: No one 17 and under admitted.
* The BBFC (British Board of Film Classification) was established in the UK [10]. The BBFC has been classifying films since 1912, offering ratings that guide the public and protect younger viewers:
* \(U\) (Universal): Suitable for all.
* \(PG\) (Parental Guidance): General viewing, but some scenes may be unsuitable for young children.
* \(12A\): Children under 12 years of age must be accompanied by an adult.
* \(15\): Only suitable for viewers aged 15 and older.
* \(18\): Only suitable for adults.
* CNC (Centre National du Cinema et de l'Image Animee) was established in France [11]. The French system, managed by the CNC, uses a stricter approach to age ratings, with a strong emphasis on protecting minors from harmful content:
* \(U\): Suitable for all.
* \(10\): Not recommended for children under 10.
* \(12\): Not recommended for children under 12.
* \(16\): Not recommended for children under 16.
* \(18\): Only suitable for adults.  
Figure 2: The schematic representation of the proposed system architecture (multiple recommender systems—MRSs).  
* FSK (Freiwillige Selbstkontrolle der Filmwritschaft) was established in Germany [12]. The German film classification system is managed by the FSK and offers the following categories:
* _0_: Suitable for all.
* _6_: Suitable for ages 6 and older.
* _12_: Suitable for ages 12 and older.
* _16_: Suitable for ages 16 and older.
* _18_: Only suitable for adults.
* The ACB (Australian Classification Board) was established in Australia [13] and has been in use since 1968. Australia's film rating system offers the following categories:
* _G_: Suitable for all.
* _PG_: Parental guidance recommended for viewers under 15.
* _M_: Recommended for viewers 15 and over.
* _MA15_+: Restricted to viewers 15 and older unless accompanied by an adult.
* _R18_+: Restricted to adult viewers (18+).
* _X18_+: Explicit adult content.  
Film age rating systems generally consider the following elements when assigning ratings: violence, sexual content, profanity, substance abuse, and themes (e.g., horror, suicide, etc.). Film age rating systems reflect the diverse cultural standards of different countries, aimed at protecting children and providing guidance to parents. Although there are similarities, the exact nature of these ratings can vary significantly, from permissiveness in one country to strict restrictions in another. The diversity of these classification systems affects the presented method since the proposed method can be adapted to any classification system providing different age classes. Furthermore, the high diversity of these classification systems underscores the utility of the proposed recommendation system in providing personalized recommendations, even for parents seeking advice on different age classes.