A meticulous assessment of the effects of parliamentary control in general is impossible because they cannot all be measured. Apart from the fact that a quantitative approach is limited and does not account for the quality of control — which can only be assessed on a case by case basis, country by country, sector by sector — it should also be noted that parliamentary control, in particular in systems of parliamentary government, sometimes follows informal procedures, especially when the majority tries to orient the action of the government that it supports in principle. The real extent of control, which tends to be confronted with similar difficulties everywhere, may vary according to the type of government system and the national specificities of parliaments.