The Gilbert model was developed by Dennis Gilbert as a means of a more effective way of classifying people in a given society into social classes.
Karl Marx believed that social class is determined by ownership (or non-ownership) of the "means of economic production" - ownership of raw materials, farm land, coal mines, factories, etc. His theory contains the idea of a struggle between two social classes - the Bourgeoisie (the capital owners) and the Proletariat (the non-owner workers).
Like Marx, Max Weber agreed that social class is determined mostly based on unequal distribution of economic power and hence the unequal distribution of opportunity. He also saw that honour, status and social prestige were key factors in determining what social class people belong to. "Life-styles" such as where a person lives and the schools they attend are very important in determining social class. "Life-chances" also determined social class. If a person becomes a respectable member of society it will raise their social class. Party affiliations can also influence social class.
Even though Marx's and Weber's research were both taken into consideration when trying to create an effective means of social stratification, they were not weighted the same. Although the Gilbert model is based on the assumption that class structure develops out of the economic system like the Marxist theory, it still has much more in common with Weber's more modern theory that dealt with socialism. The aspect that Marxism takes into consideration when referring to the economy is "what a specific person owns determines their class" - a capitalistic viewpoint. If a man owns a factory, he is going to be in a higher social class than someone who works in the factory. In Marxist theory, the middle class is not emphasized or described, but it is clearly present in the Gilbert model. The Gilbert model focuses on occupation and, more generally on the source of income (occupation for most, but also assets, and government transfers for people at the top or bottom) and when referring to how the economic system places people in classes. The occupation of a person is directly related to a person's educational preparation because better education provides for a better occupation which in turn raises their class level.