Many different things can be measured in fieldwork, for example the velocity of a river, the number of cars or the amount of litter in a particular location.
Litter counts are quantitative data
Numbers can also appear in other forms:
nominal data – these are numbers that appear as categories, e.g. 1 = yes and 2 = no
ordinal data – these numbers have an order, e.g. the rank order of cities by population size. For example, it is known that city 1 is more populated than city 2 and 3, but it is not known how many more people there are, as the spacing between each city is not equal
interval data – these numbers are similar to ordinal, but the difference between each number is equal, e.g. temperature is measured in degrees centigrade
ratio data – this is when there is a relationship between two sets of numbers, e.g. number of people per doctor