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Being able to draw a clear diagram is a basic skill that can be employed in many different situations. The purpose of a diagram is to communicate information clearly. Diagrams therefore need to be complete and easy to read. Anything that prevents the information content from being communicated to the reader is a problem and needs to be fixed. A good strategy for creating good diagrams is to make sure that they conform as far as possible to recognised standards such as UML.

Diagrams can be created with a wide range of tools. Some of them are generic drawing applications, while others are sophisticated specialist packages. As in any other situation, you should choose the appropriate tool for the task at hand. Since ER diagrams are composed of very simple elements, simple drawing tools are perfectly adequate. The majority of the ER diagrams in the materials for this module have been produced with nothing more complex than Microsoft Word. A very good (free) online alternative is which we will use to complete the exercises in this section. You must remain in control of the software and make it do what you need it to do. If you are offered a default options which is not correct, for example, you should work out how to change it so that the appearance of your diagram is the way it should be. Follow the list of actions below for a brief introduction to drawing ER diagrams with