This indicator relates the very low learning capacity in reading proficiency, This indicator relates the very low learning capacity and some relevant socioeconomic and cultural variables, such as the fact that the household has more or less than 25 books or that the educational level of the father, of the mother, or both is low.

“Very low proficiency” occurs when the score in reading is less than or equal to 407 points- the lower reading literacy score is 335 while higher reading scores are above 624 points. The ESCS indicates the economic, social and cultural status of the families of students assessed in PISA (Programme for International Student Assessment). To calculate this index the professional occupation and educational level of the parents are taken into account, along with the resources available in the household (e.g. number of books in the home).