Here is an argument essay topic from the GRE Analytical Writing Assessment. The object is to find the assumptions, or holes in logic, that make the argument less persuasive than it could be. There are at least three assumptions here:
Although the multimineral Zorba pill was designed as a simple dietary supplement, a study of first-time ulcer patients who took Zorba suggests that Zorba actually helps prevent ulcers. The study showed that only 25 percent of those ulcer patients who took Zorba under a doctor’s direction developed new ulcers, compared to a 75 percent recurrence rate among ulcer patients who did not take Zorba. Clearly, then, Zorba will be highly effective in preventing recurrent ulcers and if health experts inform the general public of this fact, many first-time ulcers can be prevented as well.
Can you spot the assumptions?