Understanding How to Check Validity with Diagrams

Chapter 8 discusses diagrams and how to check for validity. I think this is an important aspect of the chapter to understand in order to really understand the rest of the information provided in this part of the textbook. This is a summary of how to check the validity of an argument with a diagram: enclosed areas are used as representation of collections (collections is another word for a population), if this enclosed area is completely inside another enclosed area then that collection is also apart of another collection. But if only a portion of the enclosed areas is within another closed area (overlapping in some portion) then that just means that there is a similarity between the two collections. Further if two collects aren’t overlapping in any way then there is nothing similar or in common with the two collections. When looking at a diagram and seeing an “a” or dot followed by for example a persons name that means they are apart of that particular collection (this could also be an object of some sort doesn’t just have to be a person). Diagrams helpful in using to determine the validity of an argument because you can visually see what the words are stating.