How do researchers determine what is true based on the data they collect? This question is one of the central concerns of statistics, which uses mathematical models to draw useful conclusions about the real world.

Spain, officially the Kingdom of Spain, is a sovereign state and a member state of the European Union. It is located on the Iberian Peninsula in southwestern Europe. Spanish universities regulate access to their degrees, and they fix the academic fees. They can also offer unofficial postgraduate degrees. Madrid has the largest number of bars per capita of any European city and a very active nightlife.

Requirements for the PhD program often involve the student having already obtained a Master’s degree. Additionally, a thesis or dissertation primarily consisting of original academic research must be submitted. In some countries, this work may even need to be defended in front of a panel.