Tables and graphs are visual representations. They are used to organise information to show patterns and relationships. A graph shows this information by representing it as a shape. Researchers and scientists often use tables and graphs to report findings from their research. In newspapers, magazine articles, and on television they are often used to support an argument or point of view.
Why do we want students to know about tables and graphs?
Tables and graphs can be useful tools for helping people make decisions. However, they only provide part of a story. Inferences often have to be made from the data shown. As well as being able to identify clearly what the graph or table is telling us, it is important to identify what parts of the story are missing. This can help the reader decide what other information they need, or whether the argument should be rejected because the supporting evidence is suspect. Students need to know how to critique the data and the way it is presented. A table or graph can misrepresent information by
leaving out important information. Student absences gives an example of a graph with missing features.
constructing it in such a way that it misrepresents relationships. This may be because of poor skills, or it may be done deliberately to bolster a particular argument, for example using 2-dimensional shapes to inflate apparent growth. See Newspaper stories for examples of misleading graphs.
It is easy, if students are not skilful at reading graphs and tables, to interpret them incorrectly. They can make wrong decisions because they are basing them on false inferences. When constructing graphs and tables, it is also possible to misrepresent the data. Research suggests that students often regard tables and graphs as an end in themselves. Few refer to them as a source of evidence, or as a way of exploring patterns and relationships in data or information.
