Data and information can be presented in many ways, from lists and spreadsheets to charts and graphs.
Whether you are studying or in a work environment as an apprentice or employee, you will often see charts and graphs used in reports and presentations, as they are one of the best ways of communicating data, clearly and immediately.
Why do we use charts and graphs?
Charts and graphs set out data in an easy-to-understand way. Information can be taken in quickly and easily, without the need to trawl through pages of facts and figures.
Setting out data in a visual way can also help to show the relationship between different pieces of information at a glance, allowing the viewer to see patterns and analyse information more easily.
Charts and graphs can be used for business activities such as:
- Illustrating past industry trends and predicting future ones
- Analysing financial results and planning costs
- Forecasting stock orders based on past sales and future projections
- Evaluating customer satisfaction based on surveys
What are axes on charts?
An axis (plural axes) on a chart is either a horizontal or a vertical line, along which data can be recorded.
A simple line graph would have two axes: an X horizontal axis and a Y vertical axis. If you were recording how much has been spent on stationery in an office each month, you would list the figures up the side of the vertical axis (starting with zero at the bottom) and then the months of the year along the horizontal axis along the bottom of the graph.
Commonly used charts and graphs
Here are some of the most frequently used charts and graphs with an explanation of how they work.
Line graphs – one of the most common types of graph, these are useful for showing changes over time, for example house prices going up and down over a number of years. A line graph can also show several different pieces of information on one graph, for example a line each for house prices in several different areas over a number of years.
Bar charts – a bar chart or graph uses blocks or bars to represent data and, like a line graph, usually has an X and a Y axis. The blocks/bars can be displayed vertically or horizontally.
Pareto charts – these are a combination of bar chart and line graph in one chart, with three axes: a vertical on the left, a horizontal along the bottom and another vertical on the right. They allow you to illustrate a bigger range of data than would usually be found in a simple line graph or bar chart, giving a clearer picture of the relevance of various different issues.
Pie charts – are circles that are split into segments to represent different kinds of data. The segments usually represent percentages and are often given different colours. A pie chart could be used to show different sources of income in a business, or to illustrate which products are the most popular in a customer survey.
Area graphs/charts – frequently used to reflect trends, these resemble line charts but with a shaded or coloured-in area to represent volume.
Cartesian graphs – again these use an X and Y axis, but usually set out in a cross, rather than in the ‘L’ shape found in line graphs. This creates four ‘quadrants’ allowing more information to be displayed, including negative information – eg profit and loss.
Histograms – these look similar to bar charts, with vertical blocks or bars. However, while bar charts compare variables, histograms show groups of data.
Scatter graphs – again, these use vertical and horizonal axes, but the data is marked in points, which are not connected by a line as they would be on a line graph. This allows the graph to show positive and negative relationships between the variables being measured, but also cases where there is no relation between them.