Since Mary visited a realtor and herbank’s mortgage department, she must be planning on buying a home.

Step 1. Number each statementand note each indicator word.

Since (1) Mary visited a realtor and (2) herbank’s mortgage department, (3) she must be planning on buying a home.

Go to next slide.

Diagram this argument.

Since (1) Mary visited a realtor and (2) her bank’s mortgage department, (3) she must be planning on buying a home.

Step 2. Which of the claims is the conclusion? Which are premises?

(1) (2) (3)

Premise.Note the

indicator word,“Since.”

Premise. Conclusion.

Go to next slide.

Since (1) Mary visited a realtor and (2) her bank’s mortgage department, (3) she must be planning on buying a home.

Step 3. Use arrows to represent the intended relationship between the claims.

(1) (2)

(3)

In this case the premises are independent. Even though the combined force of both premises makes the argument stronger, either premise could stand alone in supporting the conclusion.

Go to next slide for another example

Argument Diagramming Sample #2

Sandra can’t register for her classes on Wednesday. After all, Sandra is a sophomore and sophomoreregistration begins on Thursday.

Step #1. Identify each claim and note any indicator words that might help identify premise(s) and conclusion(s).

(1) Sandra can’t register for her classes on Wednesday. After all, (2) Sandra is a sophomore and (3) sophomore registration begins on Thursday.

Go to next slide.

(1) Sandra can’t register for her classes on Wednesday. After all, (2) Sandra is a sophomore and (3) sophomore registration begins on Thursday.

“After all” is generallya premise indicator.

This “and” serves to jointwo different claims.

Go to next slide.

Step #2. Use arrows to show the relationships between the claims in the argument.

(2) (3)

(1)

(2) (3)

(1)

(+)

Decide whetherthe premises areindependent,

or linked.

These are linked premisessince both (in conjunction) arenecessary to prove the conclusion.

For another example go to the next slide.

Pool maintenance can cost hundreds of dollars a year and we really don’t have that kind of money. So, I don’t think we should put a pool in this summer. Besides, pools pose a real drowning danger to small children.

Step #1. The first task is to analyze the argument. Decide what the various claims are and begin to decide which are premises and which are conclusions. Number the claims and note any indicator words.

Go to next slide.

(1) Pool maintenance can cost hundreds of dollars a year and (2) we really don’t have that kind of money. So, (3) I don’t think we should put a pool in this summer. Besides, (4) pools pose a real drowning danger to small children.

Note the “and” connecting two claims.

“So” is a conclusionindicator.

A premise indicator.

Go to next slide.

Step #2. Use arrows to represent the argument.

(1) (2)

(3)

(+)

Premises 1 and 2 arelinked. While premise 1 could stand alone, premise 2 can’t.(4)

Premise 4 is independent.It could be offered alone assupport for the conclusion.

Go to the next slide.

You’ve often complained that mainstream television doesn’t have quality programming, so I think you should support public broadcasting. Besides, you watch PBS all the time and fair is fair. Since supportmeans money, you should write a check to PBS immediately.

Step #1. As before, concentrate on analyzing the various claims. Use numbers to identify them and note any indicator words.

Go to the next slide.

Go to the next slide.

This argument is more complex, but the same skills apply. What is the intended conclusion of the argument? How do the various parts of the argument work to provide support for this conclusion?

(1)You’ve often complained that mainstream television doesn’t have quality programming, so (2) I think you should support public broadcasting. Besides (3), you watch PBS all the time and (4) fairis fair. Since (5) support means money, (6) you should write a check to PBS immediately.

You can start diagramming from anywhere. Keep trying different arrangements until your diagram best represents the intended meaning of the argument.

(1)

(2)

The indicator “so” shows claim 2 to be a conclusion and 1 seems to support this conclusion.

Claims 3 and 4 offer another reason that 2 is true.

(3) (+) (4)

Go To Next Slide

What about claims 5 and 6? The “since” before 5 marks this as a premise but for which conclusion? Context and experience tell us that this is a premise supporting claim 6.

Claim 2, which says you should support PBS, combines with claim 5 which defines support as money, to support the final conclusion 6.

(1)

(2)

(3) (+) (4)

(5)

(6)

(+)

End of Tutorial