How do you construct an argument? (*Argument as in ...

An argument is simply a short summary of the book. It resembles an abstract for an academic paper or thesis but is shorter.

If you have to show the pro and con it would be best to make 2 columns. Left is pro and right is con and this way the reader can more easily follow. If you have to take only one side then you can give the pros and cons and end it with your opinion and argument to support your opinion.

Actually, Harry's tips are useful for arriving at important personal decisions, in team meetings (as at work or a club), or an outline for your formal written argument.  An argument should, like any essay have an intro, body, and conclusion.  In a strong, well-researched argument you should be able to argue for something you believe strongly against.  In the intro first propose your position, i.e., Anti-gun laws in the U.S. are to restrictive. Summarize your arguments and give a brief backgound/history about the argument, i.e., the Constitution, crime, current laws. Think of your intro as a triangle. Narrow position at point broadening to larger arguments and facts.  Then your body (this is key) should be constructed with stongest argument 1st, proceeding to weakest in middle, leading out with 2nd strongest, as in 1,3,5,4,2.  In each argument you should give counter arguments and refute them with facts and statistics or well-reasoned logic.  Make sure to cite to legitimate sources as much as possible (in footnotes or in the text of the sentence if the source is prominent).  Do not make flying assumption. A simple example, "criminals get guns mainly illegally, therefore all guns criminals use are purchased illegally."  This forgets the fact that criminals sometimes buy guns illegally (or steal them) from people who bought them legally.  Finally, think of your conlusion as an upside down triangle with broad positions first, narrowing to the point of your intial position.  In your conclusion, summarize your arguments and end the last sentence with a figurative "bang" by rephrasing your position with more force. Hope this helps.

Per purplefizz:

My teacher assigned different controversial topics to write an argument about. For example, animal rights. How would you construct an argument for that?

I like to begin arguments (in the legal sense) with a table of authorities.  Basically, you are considering all the work that has been done before, you anticipate the argument that the opposition will bring to counter your argument, and then you must decide the tone of your argument.

Are we in court, with strict evidentiary rules and codes of admissability?  Or are we in a redneck bar, where any derogatory remark about a favorite football team will get you shot? 

Then, we consider latitude of discussion.  Just how far do I need to go, to prove my point?  Must I prove a civil case (to the preponderance of evidence) or a criminal case (beyond a reasonable doubt)?

Finally, we limit the discussion.  Our argument will prove/disprove a point logically.  We must avoid -- at all costs -- trying for approval.

Okay, we have a sensitive (and highly controversial) topic.  That deserves a cautious approach and broad venue.

Let's start with the appropriate table of authorities.  What is the current law on, say, animal experimentation, vivisection, slaughter technique, and humane treatment of pets?  Don't guess at it.  Look it up and include all the data you have gathered in your bibliography: you may need to bring up these points with sound conviction.

If you are in Superior Court, your latitude of discussion will be that one single matter before the Court.  Do not deviate!  ANY evidence you present must be STRICTLY factual or it will get your case thrown out of court.  If you are making a public appeal to stop medical experimentation on animals, be sure that you have a credible alternative to the admittedly repellent practices that we see daily.

Know the actual rules of debate as accepted in your context: latitude of discussion.  Do you REALLY want to show your classmates an actual vivisection?  It is horrendous, to say the least.  Almost as distasteful, would be euthanasia in the local animal shelter, but here we begin to see the function of latitude: show the natural course of a painful disease to fatality, and then show another animal with the same condition humanely euthanized in a veterinarian's office.

The idea is to be firm, balanced, to know everything that there is to know about the subject, and sell your point under contention by fair means.

The final consideration is, the state of mind of your audience.  If you advocate anesthesia of animals before vivisection before a scientific ethics board, speak in terms that these proven professionals will understand.

If you get into a mud-slinging contest on Yedda, then kick, bite, rabbit-punch, and gouge like the rest of us.