b

• Etymology


  Explaining origin of the word itself
• History


  Discussing the history of the term/its use/controversies associated with it
• Cause and Effect


  discussing how the situation came about and what effects it may have
• Description


  Listing and defining the component parts
• Principles of Operation


  Discussing how topic in question functions, including any special materials or conditions required
• Classification


  Showing how the topic fits into a larger category
• Contrast/Negation – showing how the topic differs from others in the class.
• Comparison - comparing two different topics to show similarities and differences between them.
• Analogy - explaining by comparing two dissimilar topics, where the second is familiar to the audience.