Data can be either continuous or discrete. Continuous means that values may vary infinitely within a range; for example in the case of observations of physical measurements (e.g. when measuring the height of two animals, the difference between them can be infinitely small, and determining this is dependent only on the accuracy of the instrument used). The opposite of a continuous value is a discrete value, which means that the value cannot be divided further (e.g. the number of individuals with a certain characteristic is a discrete number, as you cannot have half of an individual).

Continuous data can be described by a graph which demonstrates how many of the individuals observed are represented by each of the values observed. A curve can then be drawn to further assist in the visual representation.

Example: Consider a number of multi-cat households. The number of cats in each household can be considered discrete data whereas the weight of each cat can be considered continuous data.

Task: Using the above example, can you think of more discrete and continuous variables that could be measured? Check the answer page for some more suggestions.