The word coherent means that something is logically connected. Based on this, <u>to express a clear and coherent argument</u> (it doesn't matter whether it is visually or in writing) it is necessary to establish an order that must be followed. This way, the author/speaker can connect ideas and make them clearer for themselves and for readers. Another important step is to revise after finishing the final version of the work so it can be corrected and clearer.
Let's say you have an idea that you want to present in writing. For an argument to be valid, it must have supporting evidence. An argument would just be useless if it did not have any documents or laws that would be supporting its justification. To say for example, I wanted to argue that the law of conservation of energy is not true. If I don't show actual evidence of energy being created, then that would leave me with an unclear, and most possibly invalid argument.
