TEAS Ready🧩 Reading · Integration of Knowledge and Ideas · Lesson 3 of 5 · 5 min
Evaluating an argument: claim, evidence and reasoning
🧠 Advertisements, opinion pieces and even health posts all make arguments. The TEAS checks whether you can tell a well-supported argument from a weak one.
💡 Key idea
Judge an argument by whether its evidence and reasoning truly support its claim, not by whether you agree.
🧠 The idea
An ARGUMENT has a CLAIM (what the author wants you to believe), EVIDENCE (facts, data, examples, expert statements) and REASONING that connects the two. To evaluate it, ask: Is the evidence relevant, recent, and enough? Does the reasoning actually lead to the claim? Common FLAWS include generalizing from one or two cases, assuming that because B followed A, A caused B, appealing to emotion or popularity instead of facts, attacking a person instead of the idea, and offering only two options when more exist. To STRENGTHEN an argument, add evidence that closes a gap, such as a larger study or a ruled-out alternative cause. To WEAKEN it, find a fact that offers another explanation or shows the evidence does not apply. Your own opinion of the claim does not matter; judge only the support.
✏️ Worked example
"Since the cafeteria started selling fruit cups, students' test scores went up, so fruit cups improve learning." Claim: fruit cups improve learning. Evidence: scores rose after the change. Flaw: it assumes the order of events proves cause. What would weaken it? Learning that a new tutoring program began the same month offers another explanation. What would strengthen it? A comparison school without fruit cups whose scores stayed flat.
📌 Takeaways
- Find the claim, then the evidence, then check the link between them.
- Watch for small samples, false cause, emotion and either-or choices.
- Another possible cause weakens; ruling one out strengthens.
📖 Terms in this lesson
Claim: The position an author argues for and tries to prove with evidence; for example, "Schools should start later in the morning."
✅ Check yourself
Question 1 of 3
"My neighbor took this herbal tea and her cold went away, so the tea cures colds." What is the main flaw?
- It attacks the people who disagree.
- It uses numbers that are out of date.
- It generalizes from one case.
- It quotes too many experts.
Show the answer and rationale
Answer: C
One neighbor's experience is far too little evidence for a general claim, and colds usually go away on their own anyway. The argument quotes no experts, uses no numbers and attacks no one.
Question 2 of 3
An author claims a new reading program raised test scores at a school. Which fact would most WEAKEN the claim?
- Teachers at the school liked the program.
- The program was used for a full school year.
- Nearby schools without it saw similar gains.
- The school's scores rose more than in past years.
Show the answer and rationale
Answer: C
If nearby schools without the program saw similar gains, something other than the program likely explains the rise, which undercuts the claim. Teacher approval and a full year of use say nothing against it, and a larger-than-usual rise would strengthen it.
Question 3 of 3
Which statement is an appeal to popularity rather than evidence?
- Readings fell an average of 8 points over 12 weeks.
- A trial of 2,000 adults found the device lowered blood pressure.
- Millions of people already own this device, so it must work.
- Doctors measured patients at the same time each day.
Show the answer and rationale
Answer: C
Saying something works because many people own it is an appeal to popularity, not proof. The trial size, the measured drop and the careful measurement method are all forms of real evidence.
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