Scientists use graphical and statistical methods to analyse patterns of data related to disease.
Data is often displayed in a graph. Graphs might display trends that are not as clear when just looking at data in a table.
Bar charts show data collected for separate groups. The height of the bar is proportional to the measured number or frequency.
This table of data and bar chart show the number of deaths that could be avoided per 100 000 of the population in England and Wales in 2013 from different causes.
|Cause of death||Avoidable deaths|
Use the information in the bar chart to find out the number of deaths that could be avoided resulting from causes other than those in the table.
Nine per 100 000 of population.
This stacked bar chart shows proportions of cases of cancer in the USA connected with the human papilloma virus (HPV), and those where no connection has been established.
Note that bar charts are sometimes displayed horizontally.
Histograms look like bar charts, but show how frequently the data occur within certain ranges.
The independent variable is therefore continuous and is divided into sub-sections or classes.
This histogram shows data from a Scottish study of the proportion of people of different ages with depression who consult their doctor. The independent variable here is age, but the histogram shows different groups within the variable of range allowing the data to be visually comparable.