The authors analysed media systems according to four dimensions: the development of a mass press, political parallelism, professionalization of journalists, and state intervention.
[4] Historically, political advocacy was seen as an important function of the print media emerging in the late 18th to early 19th century.
The role of the journalist was to influence the public towards his or her political faction or cause, something which changed only in the 19th century when journalism norms moved towards the ideal of neutrality in reporting.
[8] In Polarized Pluralist systems, political parallelism in the press played a key role in the national development, for example in Spain and Italy.
[8] Even today, as Angelika W. Wyka argues about Italy and Greece, "although the existing ethical codes are greatly thought to be a reflection of objective and impartial reporting, journalists [...] tend to be somewhat, if not extremely, partisan.
Internal pluralism is achieved within one medium, when it attempts to report neutrally and balanced, and avoids affiliations with political groups.
Polarized Pluralist media systems, for instance, are characterized by a lively public sphere, high voter turnout, strong citizen-party attachment and political participation.
[14] Polarization between these factors in the political systems of non-Western states, according to Voltmer, leads to conflicts whose structures are different from the right-left distinction of European history.
[16] Afonso de Albuquerque proposes to assess political parallelism in media systems very differently.
With regards to political parallelism, Hallin and Mancini propose to split the concept into two, following Afonso de Albuquerque’s suggestion.