They need to produce data that are easily represented as numbers, answering questions such as "How much…?", "How many…?", and "How frequent …?" Quantitative data generally require formal measurements of variables such as income, production or population densities. ###>“A quelle fréquence?” Pour obtenir des données quantitatives, il faut généralement mesurer des variables telles que le revenu, la production ou la densité démographique.